python第二天基础1-1
2024-08-24 18:12:39
一、作用域
对于变量的作用域，执行声明并在内存中存在，该变量就可以在下面的代码中使用。
if 1==1:
name = 'wupeiqi'
print name
二、三元运算
result = 值1 if 条件 else 值2 如#果条件成立，值1付给result否则值2付给result
如果条件为真：result = 值1
如果条件为假：result = 值2
name = 'sb' if 1==1 else '2b'
input = raw_input() result = '2b' if input =='alex' else 'haoren'
python基础
python里面切皆为对象，对象都是类创建的
例如：li = [11,22,33] ===类
li.append
1 类创建列表
2 类表还能返回这个类
所以说，对象所拥有的方法不是他自己所拥有的，而是从类里面找到的方法而执行的。
可以用type(li)查看对象的类型
1 <type 'list'> 这个list就是创建li的类
2 然后用dir(list) 能看到所有list下的方法---预览
3 help(list) 看详细的python的源码了---都有什么功能
4 help(list.append)---就只看append的方法
5 在pycham上按住ctrl键点在你要看的类上，就可以看了。
类中的方法可分为 1 内置方法(__add__)两头带__,他的执行方式可能有一种，也可能有多种。
2 不是内置方法,只能有一种执行方法，也就是list.append()
一、整数
如： 18、73、84
每一个整数都具备如下功能：
例如：n1 = -9
n1.__abs__()
9
或者直接abs(-9)
创建方法：前面两点相同
i = 10
i = int(10)
i = int(“10”,base=2) 创建2进制的字符是10的，
class int(object):
"""
int(x=0) -> int or long
int(x, base=10) -> int or long Convert a number or string to an integer, or return 0 if no arguments
are given. If x is floating point, the conversion truncates towards zero.
If x is outside the integer range, the function returns a long instead. If x is not a number or if base is given, then x must be a string or
Unicode object representing an integer literal in the given base. The
literal can be preceded by '+' or '-' and be surrounded by whitespace.
The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to
interpret the base from the string as an integer literal.
>>> int('0b100', base=0)
4
"""
def bit_length(self):
""" 返回表示该数字的时占用的最少位数 """
"""
int.bit_length() -> int Number of bits necessary to represent self in binary.
>>> bin(37)
'0b100101'
>>> (37).bit_length()
6
"""
return 0 def conjugate(self, *args, **kwargs): # real signature unknown
""" 返回该复数的共轭复数 """
""" Returns self, the complex conjugate of any int. """
pass def __abs__(self):
""" 返回绝对值 """
""" x.__abs__() <==> abs(x) """
pass def __add__(self, y):
""" x.__add__(y) <==> x+y """
pass
#age = 18
#age.__add__(199)==18+199
def __and__(self, y):
""" x.__and__(y) <==> x&y """
pass def __cmp__(self, y):
""" 比较两个数大小 """
""" x.__cmp__(y) <==> cmp(x,y) """ 大于为1 等于为0 小于为-1
pass def __coerce__(self, y):
""" 强制生成一个元组 """
""" x.__coerce__(y) <==> coerce(x, y) """
pass
def __divmod__(self, y): """ 相除，得到商和余数组成的元组 """网页上分页用 """ x.__divmod__(y) <==> divmod(x, y) """ pass
def __div__(self, y):
""" x.__div__(y) <==> x/y """
pass def __float__(self):
""" 转换为浮点类型 """
""" x.__float__() <==> float(x) """
pass def __floordiv__(self, y):
""" x.__floordiv__(y) <==> x//y """ 底板除
pass def __format__(self, *args, **kwargs): # real signature unknown
pass def __getattribute__(self, name):
""" x.__getattribute__('name') <==> x.name """
pass def __getnewargs__(self, *args, **kwargs): # real signature unknown
""" 内部调用 __new__方法或创建对象时传入参数使用 """
pass def __hash__(self):
"""如果对象object为哈希表类型，返回对象object的哈希值。哈希值为整数。在字典查找中，哈希值用于快速比较字典的键。两个数值如果相等，则哈希值也相等。"""
""" x.__hash__() <==> hash(x) """
pass def __hex__(self):
""" 返回当前数的 十六进制 表示 """
""" x.__hex__() <==> hex(x) """
pass def __index__(self):
""" 用于切片，数字无意义 """
""" x[y:z] <==> x[y.__index__():z.__index__()] """
pass def __init__(self, x, base=10): # known special case of int.__init__
""" 构造方法，执行 x = 123 或 x = int(10) 时，自动调用，暂时忽略 """
"""
int(x=0) -> int or long
int(x, base=10) -> int or long Convert a number or string to an integer, or return 0 if no arguments
are given. If x is floating point, the conversion truncates towards zero.
If x is outside the integer range, the function returns a long instead. If x is not a number or if base is given, then x must be a string or
Unicode object representing an integer literal in the given base. The
literal can be preceded by '+' or '-' and be surrounded by whitespace.
The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to
interpret the base from the string as an integer literal.
>>> int('0b100', base=0)
4
# (copied from class doc)
"""
pass def __int__(self):
""" 转换为整数 """
""" x.__int__() <==> int(x) """
pass def __invert__(self):
""" x.__invert__() <==> ~x """
pass def __long__(self):
""" 转换为长整数 """
""" x.__long__() <==> long(x) """
pass def __lshift__(self, y):
""" x.__lshift__(y) <==> x<<y """
pass def __mod__(self, y):
""" x.__mod__(y) <==> x%y """
pass def __mul__(self, y):
""" x.__mul__(y) <==> x*y """
pass def __neg__(self):
""" x.__neg__() <==> -x """
pass @staticmethod # known case of __new__
def __new__(S, *more):
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __nonzero__(self):
""" x.__nonzero__() <==> x != 0 """
pass def __oct__(self):
""" 返回改值的 八进制 表示 """
""" x.__oct__() <==> oct(x) """
pass def __or__(self, y):
""" x.__or__(y) <==> x|y """
pass def __pos__(self):
""" x.__pos__() <==> +x """
pass def __pow__(self, y, z=None):
""" 幂，次方 """2**8
""" x.__pow__(y[, z]) <==> pow(x, y[, z]) """
pass def __radd__(self, y):
""" x.__radd__(y) <==> y+x """
pass def __rand__(self, y):
""" x.__rand__(y) <==> y&x """
pass def __rdivmod__(self, y):
""" x.__rdivmod__(y) <==> divmod(y, x) """
pass def __rdiv__(self, y):
""" x.__rdiv__(y) <==> y/x """
pass def __repr__(self):
"""转化为解释器可读取的形式 """
""" x.__repr__() <==> repr(x) """
pass def __str__(self):
"""转换为人阅读的形式，如果没有适于人阅读的解释形式的话，则返回解释器课阅读的形式"""
""" x.__str__() <==> str(x) """
pass def __rfloordiv__(self, y):
""" x.__rfloordiv__(y) <==> y//x """
pass def __rlshift__(self, y):
""" x.__rlshift__(y) <==> y<<x """
pass def __rmod__(self, y):
""" x.__rmod__(y) <==> y%x """
pass def __rmul__(self, y):
""" x.__rmul__(y) <==> y*x """
pass def __ror__(self, y):
""" x.__ror__(y) <==> y|x """
pass def __rpow__(self, x, z=None):
""" y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
pass def __rrshift__(self, y):
""" x.__rrshift__(y) <==> y>>x """
pass def __rshift__(self, y):
""" x.__rshift__(y) <==> x>>y """
pass def __rsub__(self, y):
""" x.__rsub__(y) <==> y-x """
pass def __rtruediv__(self, y):
""" x.__rtruediv__(y) <==> y/x """
pass def __rxor__(self, y):
""" x.__rxor__(y) <==> y^x """
pass def __sub__(self, y):
""" x.__sub__(y) <==> x-y """
pass def __truediv__(self, y):
""" x.__truediv__(y) <==> x/y """
pass def __trunc__(self, *args, **kwargs):
""" 返回数值被截取为整形的值，在整形中无意义 """
pass def __xor__(self, y):
""" x.__xor__(y) <==> x^y """
pass denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 分母 = 1 """
"""the denominator of a rational number in lowest terms""" imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 虚数，无意义 """
"""the imaginary part of a complex number""" numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 分子 = 数字大小 """
"""the numerator of a rational number in lowest terms""" real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 实属，无意义 """
"""the real part of a complex number"""
int
二、长整型
可能如：2147483649、9223372036854775807
每个长整型都具备如下功能：
class long(object):
"""
long(x=0) -> long
long(x, base=10) -> long Convert a number or string to a long integer, or return 0L if no arguments
are given. If x is floating point, the conversion truncates towards zero. If x is not a number or if base is given, then x must be a string or
Unicode object representing an integer literal in the given base. The
literal can be preceded by '+' or '-' and be surrounded by whitespace.
The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to
interpret the base from the string as an integer literal.
>>> int('0b100', base=0)
4L
"""
def bit_length(self): # real signature unknown; restored from __doc__
"""
long.bit_length() -> int or long Number of bits necessary to represent self in binary.
>>> bin(37L)
'0b100101'
>>> (37L).bit_length()
6
"""
return 0 def conjugate(self, *args, **kwargs): # real signature unknown
""" Returns self, the complex conjugate of any long. """
pass def __abs__(self): # real signature unknown; restored from __doc__
""" x.__abs__() <==> abs(x) """
pass def __add__(self, y): # real signature unknown; restored from __doc__
""" x.__add__(y) <==> x+y """
pass def __and__(self, y): # real signature unknown; restored from __doc__
""" x.__and__(y) <==> x&y """
pass def __cmp__(self, y): # real signature unknown; restored from __doc__
""" x.__cmp__(y) <==> cmp(x,y) """
pass def __coerce__(self, y): # real signature unknown; restored from __doc__
""" x.__coerce__(y) <==> coerce(x, y) """
pass def __divmod__(self, y): # real signature unknown; restored from __doc__
""" x.__divmod__(y) <==> divmod(x, y) """
pass def __div__(self, y): # real signature unknown; restored from __doc__
""" x.__div__(y) <==> x/y """
pass def __float__(self): # real signature unknown; restored from __doc__
""" x.__float__() <==> float(x) """
pass def __floordiv__(self, y): # real signature unknown; restored from __doc__
""" x.__floordiv__(y) <==> x//y """
pass def __format__(self, *args, **kwargs): # real signature unknown
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass def __hash__(self): # real signature unknown; restored from __doc__
""" x.__hash__() <==> hash(x) """
pass def __hex__(self): # real signature unknown; restored from __doc__
""" x.__hex__() <==> hex(x) """
pass def __index__(self): # real signature unknown; restored from __doc__
""" x[y:z] <==> x[y.__index__():z.__index__()] """
pass def __init__(self, x=0): # real signature unknown; restored from __doc__
pass def __int__(self): # real signature unknown; restored from __doc__
""" x.__int__() <==> int(x) """
pass def __invert__(self): # real signature unknown; restored from __doc__
""" x.__invert__() <==> ~x """
pass def __long__(self): # real signature unknown; restored from __doc__
""" x.__long__() <==> long(x) """
pass def __lshift__(self, y): # real signature unknown; restored from __doc__
""" x.__lshift__(y) <==> x<<y """
pass def __mod__(self, y): # real signature unknown; restored from __doc__
""" x.__mod__(y) <==> x%y """
pass def __mul__(self, y): # real signature unknown; restored from __doc__
""" x.__mul__(y) <==> x*y """
pass def __neg__(self): # real signature unknown; restored from __doc__
""" x.__neg__() <==> -x """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __nonzero__(self): # real signature unknown; restored from __doc__
""" x.__nonzero__() <==> x != 0 """
pass def __oct__(self): # real signature unknown; restored from __doc__
""" x.__oct__() <==> oct(x) """
pass def __or__(self, y): # real signature unknown; restored from __doc__
""" x.__or__(y) <==> x|y """
pass def __pos__(self): # real signature unknown; restored from __doc__
""" x.__pos__() <==> +x """
pass def __pow__(self, y, z=None): # real signature unknown; restored from __doc__
""" x.__pow__(y[, z]) <==> pow(x, y[, z]) """
pass def __radd__(self, y): # real signature unknown; restored from __doc__
""" x.__radd__(y) <==> y+x """
pass def __rand__(self, y): # real signature unknown; restored from __doc__
""" x.__rand__(y) <==> y&x """
pass def __rdivmod__(self, y): # real signature unknown; restored from __doc__
""" x.__rdivmod__(y) <==> divmod(y, x) """
pass def __rdiv__(self, y): # real signature unknown; restored from __doc__
""" x.__rdiv__(y) <==> y/x """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __rfloordiv__(self, y): # real signature unknown; restored from __doc__
""" x.__rfloordiv__(y) <==> y//x """
pass def __rlshift__(self, y): # real signature unknown; restored from __doc__
""" x.__rlshift__(y) <==> y<<x """
pass def __rmod__(self, y): # real signature unknown; restored from __doc__
""" x.__rmod__(y) <==> y%x """
pass def __rmul__(self, y): # real signature unknown; restored from __doc__
""" x.__rmul__(y) <==> y*x """
pass def __ror__(self, y): # real signature unknown; restored from __doc__
""" x.__ror__(y) <==> y|x """
pass def __rpow__(self, x, z=None): # real signature unknown; restored from __doc__
""" y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
pass def __rrshift__(self, y): # real signature unknown; restored from __doc__
""" x.__rrshift__(y) <==> y>>x """
pass def __rshift__(self, y): # real signature unknown; restored from __doc__
""" x.__rshift__(y) <==> x>>y """
pass def __rsub__(self, y): # real signature unknown; restored from __doc__
""" x.__rsub__(y) <==> y-x """
pass def __rtruediv__(self, y): # real signature unknown; restored from __doc__
""" x.__rtruediv__(y) <==> y/x """
pass def __rxor__(self, y): # real signature unknown; restored from __doc__
""" x.__rxor__(y) <==> y^x """
pass def __sizeof__(self, *args, **kwargs): # real signature unknown
""" Returns size in memory, in bytes """
pass def __str__(self): # real signature unknown; restored from __doc__
""" x.__str__() <==> str(x) """
pass def __sub__(self, y): # real signature unknown; restored from __doc__
""" x.__sub__(y) <==> x-y """
pass def __truediv__(self, y): # real signature unknown; restored from __doc__
""" x.__truediv__(y) <==> x/y """
pass def __trunc__(self, *args, **kwargs): # real signature unknown
""" Truncating an Integral returns itself. """
pass def __xor__(self, y): # real signature unknown; restored from __doc__
""" x.__xor__(y) <==> x^y """
pass denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""the denominator of a rational number in lowest terms""" imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""the imaginary part of a complex number""" numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""the numerator of a rational number in lowest terms""" real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""the real part of a complex number"""
复制代码
long
三、浮点型
如：3.14、2.88
每个浮点型都具备如下功能：
class float(object):
"""
float(x) -> floating point number Convert a string or number to a floating point number, if possible.
"""
def as_integer_ratio(self):
""" 获取改值的最简比 """
"""
float.as_integer_ratio() -> (int, int) Return a pair of integers, whose ratio is exactly equal to the original
float and with a positive denominator.
Raise OverflowError on infinities and a ValueError on NaNs. >>> (10.0).as_integer_ratio()
(10, 1)
>>> (0.0).as_integer_ratio()
(0, 1)
>>> (-.25).as_integer_ratio()
(-1, 4)
"""
pass def conjugate(self, *args, **kwargs): # real signature unknown
""" Return self, the complex conjugate of any float. """
pass def fromhex(self, string):
""" 将十六进制字符串转换成浮点型 """
"""
float.fromhex(string) -> float Create a floating-point number from a hexadecimal string.
>>> float.fromhex('0x1.ffffp10')
2047.984375
>>> float.fromhex('-0x1p-1074')
-4.9406564584124654e-324
"""
return 0.0 def hex(self):
""" 返回当前值的 16 进制表示 """
"""
float.hex() -> string Return a hexadecimal representation of a floating-point number.
>>> (-0.1).hex()
'-0x1.999999999999ap-4'
>>> 3.14159.hex()
'0x1.921f9f01b866ep+1'
"""
return "" def is_integer(self, *args, **kwargs): # real signature unknown
""" Return True if the float is an integer. """
pass def __abs__(self):
""" x.__abs__() <==> abs(x) """
pass def __add__(self, y):
""" x.__add__(y) <==> x+y """
pass def __coerce__(self, y):
""" x.__coerce__(y) <==> coerce(x, y) """
pass def __divmod__(self, y):
""" x.__divmod__(y) <==> divmod(x, y) """
pass def __div__(self, y):
""" x.__div__(y) <==> x/y """
pass def __eq__(self, y):
""" x.__eq__(y) <==> x==y """
pass def __float__(self):
""" x.__float__() <==> float(x) """
pass def __floordiv__(self, y):
""" x.__floordiv__(y) <==> x//y """
pass def __format__(self, format_spec):
"""
float.__format__(format_spec) -> string Formats the float according to format_spec.
"""
return "" def __getattribute__(self, name):
""" x.__getattribute__('name') <==> x.name """
pass def __getformat__(self, typestr):
"""
float.__getformat__(typestr) -> string You probably don't want to use this function. It exists mainly to be
used in Python's test suite. typestr must be 'double' or 'float'. This function returns whichever of
'unknown', 'IEEE, big-endian' or 'IEEE, little-endian' best describes the
format of floating point numbers used by the C type named by typestr.
"""
return "" def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass def __ge__(self, y):
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y):
""" x.__gt__(y) <==> x>y """
pass def __hash__(self):
""" x.__hash__() <==> hash(x) """
pass def __init__(self, x):
pass def __int__(self):
""" x.__int__() <==> int(x) """
pass def __le__(self, y):
""" x.__le__(y) <==> x<=y """
pass def __long__(self):
""" x.__long__() <==> long(x) """
pass def __lt__(self, y):
""" x.__lt__(y) <==> x<y """
pass def __mod__(self, y):
""" x.__mod__(y) <==> x%y """
pass def __mul__(self, y):
""" x.__mul__(y) <==> x*y """
pass def __neg__(self):
""" x.__neg__() <==> -x """
pass @staticmethod # known case of __new__
def __new__(S, *more):
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y):
""" x.__ne__(y) <==> x!=y """
pass def __nonzero__(self):
""" x.__nonzero__() <==> x != 0 """
pass def __pos__(self):
""" x.__pos__() <==> +x """
pass def __pow__(self, y, z=None):
""" x.__pow__(y[, z]) <==> pow(x, y[, z]) """
pass def __radd__(self, y):
""" x.__radd__(y) <==> y+x """
pass def __rdivmod__(self, y):
""" x.__rdivmod__(y) <==> divmod(y, x) """
pass def __rdiv__(self, y):
""" x.__rdiv__(y) <==> y/x """
pass def __repr__(self):
""" x.__repr__() <==> repr(x) """
pass def __rfloordiv__(self, y):
""" x.__rfloordiv__(y) <==> y//x """
pass def __rmod__(self, y):
""" x.__rmod__(y) <==> y%x """
pass def __rmul__(self, y):
""" x.__rmul__(y) <==> y*x """
pass def __rpow__(self, x, z=None):
""" y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
pass def __rsub__(self, y):
""" x.__rsub__(y) <==> y-x """
pass def __rtruediv__(self, y):
""" x.__rtruediv__(y) <==> y/x """
pass def __setformat__(self, typestr, fmt):
"""
float.__setformat__(typestr, fmt) -> None You probably don't want to use this function. It exists mainly to be
used in Python's test suite. typestr must be 'double' or 'float'. fmt must be one of 'unknown',
'IEEE, big-endian' or 'IEEE, little-endian', and in addition can only be
one of the latter two if it appears to match the underlying C reality. Override the automatic determination of C-level floating point type.
This affects how floats are converted to and from binary strings.
"""
pass def __str__(self):
""" x.__str__() <==> str(x) """
pass def __sub__(self, y):
""" x.__sub__(y) <==> x-y """
pass def __truediv__(self, y):
""" x.__truediv__(y) <==> x/y """
pass def __trunc__(self, *args, **kwargs): # real signature unknown
""" Return the Integral closest to x between 0 and x. """
pass imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""the imaginary part of a complex number""" real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""the real part of a complex number"""
float
四、字符串
如：'wupeiqi'、'alex'
怎样创建字符串：
1 str1 = “Alex”
2 str1 = str（“Alex”） 用str类创建了str1
解码与编码
gbk ---->utf-8
str1,decode(‘gbk’).encode(‘utf-8’) (先解码成unicode在编码成utf-8)
字符串的格式化方法：
1
2
3
可以传递一个类表或者数组进去，例如：
name = ”i am {0},age {1}”
li = [11,22]
name.format(*li) 在列表前一定要加一个*，就是这个规定的。
4
可以传递一个字典进去，例如
name = “i an {ss},age {dd}”
dic = {‘ss’:123,’dd’:456}
name.format(**dic) 传递字典要在前面加**。
print('{}{}'.format('name','age'))
print ('{name}'.format(name='sun'))
print('{0}{1}{0}'.format('sun','bo'))
5 字符串切片,记住顾头不顾尾原则.
msg= 12345
print msg[0:4]
1234
每个字符串都具备如下功能：
class str(basestring):
"""
str(object='') -> string Return a nice string representation of the object.
If the argument is a string, the return value is the same object.
"""
def capitalize(self):
""" 首字母变大写 """
"""
S.capitalize() -> string Return a copy of the string S with only its first character
capitalized.
"""
return "" def center(self, width, fillchar=None):
""" 内容居中，width：总长度；fillchar：空白处填充内容，默认无 """
"""
S.center(width[, fillchar]) -> string Return S centered in a string of length width. Padding is
done using the specified fill character (default is a space)
"""
return "" def count(self, sub, start=None, end=None):
""" 子序列个数 start其实就是下标的意思 """
"""
S.count(sub[, start[, end]]) -> int Return the number of non-overlapping occurrences of substring sub in
string S[start:end]. Optional arguments start and end are interpreted
as in slice notation.
"""
return 0 def decode(self, encoding=None, errors=None):
""" 解码 """
"""
S.decode([encoding[,errors]]) -> object Decodes S using the codec registered for encoding. encoding defaults
to the default encoding. errors may be given to set a different error
handling scheme. Default is 'strict' meaning that encoding errors raise
a UnicodeDecodeError. Other possible values are 'ignore' and 'replace'
as well as any other name registered with codecs.register_error that is
able to handle UnicodeDecodeErrors.
"""
return object() def encode(self, encoding=None, errors=None):
""" 编码，针对unicode """
"""
S.encode([encoding[,errors]]) -> object Encodes S using the codec registered for encoding. encoding defaults
to the default encoding. errors may be given to set a different error
handling scheme. Default is 'strict' meaning that encoding errors raise
a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
'xmlcharrefreplace' as well as any other name registered with
codecs.register_error that is able to handle UnicodeEncodeErrors.
"""
return object() def endswith(self, suffix, start=None, end=None):
""" 是否以 xxx 结束 """
"""
S.endswith(suffix[, start[, end]]) -> bool Return True if S ends with the specified suffix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
suffix can also be a tuple of strings to try.
"""
return False def expandtabs(self, tabsize=None):
""" 将tab转换成空格，默认一个tab转换成8个空格 """
"""
S.expandtabs([tabsize]) -> string Return a copy of S where all tab characters are expanded using spaces.
If tabsize is not given, a tab size of 8 characters is assumed.
"""
return "" def find(self, sub, start=None, end=None):
""" 寻找子序列位置，如果没找到，返回 -1 """
如果找的是两个字母，则找到的结果以第一个字母为准 """
S.find(sub [,start [,end]]) -> int Return the lowest index in S where substring sub is found,
such that sub is contained within S[start:end]. Optional
arguments start and end are interpreted as in slice notation. Return -1 on failure.
"""
return 0 def format(*args, **kwargs): # known special case of str.format
""" 字符串格式化，动态参数，将函数式编程时细说 """
"""
S.format(*args, **kwargs) -> string Return a formatted version of S, using substitutions from args and kwargs.
The substitutions are identified by braces ('{' and '}').
"""
pass def index(self, sub, start=None, end=None):
""" 子序列位置，如果没找到，报错 """
S.index(sub [,start [,end]]) -> int Like S.find() but raise ValueError when the substring is not found.
"""
return 0 def isalnum(self):
""" 是否是字母和数字 """
"""
S.isalnum() -> bool Return True if all characters in S are alphanumeric
and there is at least one character in S, False otherwise.
"""
return False def isalpha(self):
""" 是否是字母 """
"""
S.isalpha() -> bool Return True if all characters in S are alphabetic
and there is at least one character in S, False otherwise.
"""
return False def isdigit(self):
""" 是否是数字 """
"""
S.isdigit() -> bool Return True if all characters in S are digits
and there is at least one character in S, False otherwise.
"""
return False def islower(self):
""" 是否小写 """
"""
S.islower() -> bool Return True if all cased characters in S are lowercase and there is
at least one cased character in S, False otherwise.
"""
return False def isspace(self):
"""
S.isspace() -> bool
是否是空格
Return True if all characters in S are whitespace
and there is at least one character in S, False otherwise.
"""
return False def istitle(self):
""" 是否是标题
S.istitle() -> bool Return True if S is a titlecased string and there is at least one
character in S, i.e. uppercase characters may only follow uncased
characters and lowercase characters only cased ones. Return False
otherwise.
"""
return False def isupper(self):
"""
是不是全是大写
S.isupper() -> bool
Return True if all cased characters in S are uppercase and there is
at least one cased character in S, False otherwise.
"""
return False
def join(self, iterable):
""" 连接 """
"""
S.join(iterable) -> string
li = [‘s1’,’s2’]
‘_’.join(li)
‘s1_s2’
Return a string which is the concatenation of the strings in the
iterable. The separator between elements is S.
"""
return "" def ljust(self, width, fillchar=None):
""" 内容左对齐，右侧填充 """
"""
S.ljust(width[, fillchar]) -> string Return S left-justified in a string of length width. Padding is
done using the specified fill character (default is a space).
"""
return "" def lower(self):
""" 变小写 """
"""
S.lower() -> string Return a copy of the string S converted to lowercase.
"""
return "" def lstrip(self, chars=None):
""" 移除左侧空白 """
"""
S.lstrip([chars]) -> string or unicode Return a copy of the string S with leading whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
"""
return "" def partition(self, sep):
""" 分割，前，中，后三部分 """
"""
S.partition(sep) -> (head, sep, tail) Search for the separator sep in S, and return the part before it,
the separator itself, and the part after it. If the separator is not
found, return S and two empty strings.
"""
pass def replace(self, old, new, count=None):
""" 替换 """
"""
S.replace(old, new[, count]) -> string Return a copy of string S with all occurrences of substring
old replaced by new. If the optional argument count is
given, only the first count occurrences are replaced.
"""
return "" def rfind(self, sub, start=None, end=None):
"""
S.rfind(sub [,start [,end]]) -> int Return the highest index in S where substring sub is found,
such that sub is contained within S[start:end]. Optional
arguments start and end are interpreted as in slice notation. Return -1 on failure.
"""
return 0 def rindex(self, sub, start=None, end=None):
"""
S.rindex(sub [,start [,end]]) -> int Like S.rfind() but raise ValueError when the substring is not found.
"""
return 0 def rjust(self, width, fillchar=None):
"""
S.rjust(width[, fillchar]) -> string Return S right-justified in a string of length width. Padding is
done using the specified fill character (default is a space)
"""
return "" def rpartition(self, sep):
"""
S.rpartition(sep) -> (head, sep, tail) Search for the separator sep in S, starting at the end of S, and return
the part before it, the separator itself, and the part after it. If the
separator is not found, return two empty strings and S.
"""
pass def rsplit(self, sep=None, maxsplit=None):
"""
S.rsplit([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the
delimiter string, starting at the end of the string and working
to the front. If maxsplit is given, at most maxsplit splits are
done. If sep is not specified or is None, any whitespace string
is a separator.
"""
return [] def rstrip(self, chars=None):
"""
S.rstrip([chars]) -> string or unicode Return a copy of the string S with trailing whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
"""
return "" def split(self, sep=None, maxsplit=None):
""" 分割， maxsplit最多分割几次 """
"""
S.split([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the
delimiter string. If maxsplit is given, at most maxsplit
splits are done. If sep is not specified or is None, any
whitespace string is a separator and empty strings are removed
from the result.
"""
return [] def splitlines(self, keepends=False):
""" 根据换行分割 """
"""
S.splitlines(keepends=False) -> list of strings Return a list of the lines in S, breaking at line boundaries.
Line breaks are not included in the resulting list unless keepends
is given and true.
"""
return [] def startswith(self, prefix, start=None, end=None):
""" 是否起始 """
"""
S.startswith(prefix[, start[, end]]) -> bool Return True if S starts with the specified prefix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
prefix can also be a tuple of strings to try.
"""
return False def strip(self, chars=None):
""" 移除两段空白 """
"""
S.strip([chars]) -> string or unicode Return a copy of the string S with leading and trailing
whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
"""
return "" def swapcase(self):
""" 大写变小写，小写变大写 """
"""
S.swapcase() -> string Return a copy of the string S with uppercase characters
converted to lowercase and vice versa.
"""
return "" def title(self):
"""
S.title() -> string
变成标题格式
Return a titlecased version of S, i.e. words start with uppercase
characters, all remaining cased characters have lowercase.
"""
return "" def translate(self, table, deletechars=None):
"""
转换，需要先做一个对应表，最后一个表示删除字符集合
import string
intab = "aeiou"
outtab = ""
trantab = string.maketrans(intab, outtab)
str = "this is string example....wow!!!"
print str.translate(trantab, 'xm')
"""
先删在转换
"""
S.translate(table [,deletechars]) -> string Return a copy of the string S, where all characters occurring
in the optional argument deletechars are removed, and the
remaining characters have been mapped through the given
translation table, which must be a string of length 256 or None.
If the table argument is None, no translation is applied and
the operation simply removes the characters in deletechars.
"""
return "" def upper(self):
"""
S.upper() -> string Return a copy of the string S converted to uppercase.
"""
return "" def zfill(self, width):
"""方法返回指定长度的字符串，原字符串右对齐，前面填充0。"""
"""
S.zfill(width) -> string Pad a numeric string S with zeros on the left, to fill a field
of the specified width. The string S is never truncated.
"""
return "" def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown
pass def _formatter_parser(self, *args, **kwargs): # real signature unknown
pass def __add__(self, y):
""" x.__add__(y) <==> x+y """
pass def __contains__(self, y):
""" x.__contains__(y) <==> y in x """
pass def __eq__(self, y):
""" x.__eq__(y) <==> x==y """
pass def __format__(self, format_spec):
"""
S.__format__(format_spec) -> string Return a formatted version of S as described by format_spec.
"""
return "" def __getattribute__(self, name):
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y):
""" x.__getitem__(y) <==> x[y] """
pass def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass def __getslice__(self, i, j):
"""
x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported.
"""
pass def __ge__(self, y):
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y):
""" x.__gt__(y) <==> x>y """
pass def __hash__(self):
""" x.__hash__() <==> hash(x) """
pass def __init__(self, string=''): # known special case of str.__init__
"""
str(object='') -> string Return a nice string representation of the object.
If the argument is a string, the return value is the same object.
# (copied from class doc)
"""
pass def __len__(self):
""" x.__len__() <==> len(x) """
pass def __le__(self, y):
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y):
""" x.__lt__(y) <==> x<y """
pass def __mod__(self, y):
""" x.__mod__(y) <==> x%y """
pass def __mul__(self, n):
""" x.__mul__(n) <==> x*n """
pass @staticmethod # known case of __new__
def __new__(S, *more):
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y):
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self):
""" x.__repr__() <==> repr(x) """
pass def __rmod__(self, y):
""" x.__rmod__(y) <==> y%x """
pass def __rmul__(self, n):
""" x.__rmul__(n) <==> n*x """
pass def __sizeof__(self):
""" S.__sizeof__() -> size of S in memory, in bytes """
pass def __str__(self):
""" x.__str__() <==> str(x) """
pass str
str
注：编码；字符串的乘法；字符串和格式化
作业：
多级字典：
# -*- coding: utf-8 -*-
menu = {
'北京':{
'海淀':{
'五道口':{
'soho':{},
'网易':{},
'google':{}
},
'中关村':{
'爱奇艺':{},
'汽车之家':{},
'youku':{},
},
'上地':{
'百度':{},
},
},
'昌平':{
'沙河':{
'老男孩':{},
'北航':{},
},
'天通苑':{},
'回龙观':{},
},
'朝阳':{},
'东城':{},
},
'上海':{
'闵行':{
"人民广场":{
'炸鸡店':{}
}
},
'闸北':{
'火车战':{
'携程':{}
}
},
'浦东':{},
},
'山东':{},
}
current_level=menu###当前层
last_level=[] ##父亲层
while True:
for key in current_level:
print(key)
choice=input(">>>:").strip()
if len(choice)==0:continue
if choice=="quit":
#if not last_level:break ###和一下行是一个意思
if len(last_level)==0:break##最后一层，就退出程序
current_level=last_level[-1]##把当前层改成父亲层，下一次循环就回到上一次层
last_level.pop()
if choice not in current_level:continue###如果输入的不在里边，从新输入
last_level.append(current_level)###记住当前层，
current_level=current_level[choice]##进入下一层
代码
运算符
算数运算
比较运算
赋值运算
逻辑运算
成员运算
身份运算
位运算
运算符的优先级
布尔值:
非零数字自带的布尔值都是true
非空字符串自带的布尔值都是true
五、列表
如：[11,22,33]、['wupeiqi', 'alex']
每个列表都具备如下功能：
class list(object):
"""
list() -> new empty list
list(iterable) -> new list initialized from iterable's items
"""
def append(self, p_object): # real signature unknown; restored from __doc__
""" L.append(object) -- append object to end 把值添加到列表的后面"""
pass def count(self, value): # real signature unknown; restored from __doc__
""" L.count(value) -> integer -- return number of occurrences of value 出现的值的次数 """
return 0 def extend(self, iterable): # real signature unknown; restored from __doc__
""" L.extend(iterable) -- extend list by appending elements from the iterable 扩展类表，在原列表中可以扩展 li.extend([‘rice’]) id 不变 """
pass def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
"""
L.index(value, [start, [stop]]) -> integer -- return first index of value.
Raises ValueError if the value is not present.
"""
return 0 def insert(self, index, p_object): # real signature unknown; restored from __doc__
""" L.insert(index, object) -- insert object before index 在列表指定位置插入"""
pass def pop(self, index=None): # real signature unknown; restored from __doc__
"""
L.pop([index]) -> item -- remove and return item at index (default last).
Raises IndexError if list is empty or index is out of range.
"""
删除并返回指定下标的值，如果没有指定，默认是最后一个值
li = [111,222,333]
name = li.pop()
name
333
pass def remove(self, value): # real signature unknown; restored from __doc__
"""
L.remove(value) -- remove first occurrence of value.
Raises ValueError if the value is not present.
""" 移除类表的中元素，这是指定值的,只移除第一个 li.remove(222)
pass def reverse(self): # real signature unknown; restored from __doc__
""" L.reverse() -- reverse *IN PLACE* 翻转 ，也就是顺序颠倒一下"""
pass def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__
"""
L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
cmp(x, y) -> -1, 0, 1
""" 数字--大小比较 字符----ak吗 中文—ncode
pass def __add__(self, y): # real signature unknown; restored from __doc__
""" x.__add__(y) <==> x+y """
pass def __contains__(self, y): # real signature unknown; restored from __doc__
""" x.__contains__(y) <==> y in x """
pass def __delitem__(self, y): # real signature unknown; restored from __doc__
""" x.__delitem__(y) <==> del x[y] """
pass del li[1]默认就会调用这个delitem这个方法 def __delslice__(self, i, j): # real signature unknown; restored from __doc__
"""
x.__delslice__(i, j) <==> del x[i:j] Use of negative indices is not supported.
"""
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y): # real signature unknown; restored from __doc__
""" x.__getitem__(y) <==> x[y] """
pass def __getslice__(self, i, j): # real signature unknown; restored from __doc__
"""
x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported.
"""
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __iadd__(self, y): # real signature unknown; restored from __doc__
""" x.__iadd__(y) <==> x+=y """
pass def __imul__(self, y): # real signature unknown; restored from __doc__
""" x.__imul__(y) <==> x*=y """
pass def __init__(self, seq=()): # known special case of list.__init__
"""
list() -> new empty list
list(iterable) -> new list initialized from iterable's items
# (copied from class doc)
"""
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass def __mul__(self, n): # real signature unknown; restored from __doc__
""" x.__mul__(n) <==> x*n """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __reversed__(self): # real signature unknown; restored from __doc__
""" L.__reversed__() -- return a reverse iterator over the list """
pass def __rmul__(self, n): # real signature unknown; restored from __doc__
""" x.__rmul__(n) <==> n*x """
pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__
""" x.__setitem__(i, y) <==> x[i]=y """
pass def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__
"""
x.__setslice__(i, j, y) <==> x[i:j]=y Use of negative indices is not supported.
"""
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" L.__sizeof__() -- size of L in memory, in bytes """
pass __hash__ = None
list
列表的循环
name = [["gaolong",29],["wangyuangeng",26],["sunlixue",21],["sunbo",30],["tiansuli",23]]
for i,ele in enumerate(name):
print (i,".",ele[0],ele[1])
0 . gaolong
1 . wangyuangeng
2 . sunlixue
3 . sunbo
4 . tiansuli
注：排序；
六、元组
如：(11,22,33)、('wupeiqi', 'alex') 不可修改----元组的元素不能被修改，元组的元素的元素是可以被修改的
每个元组都具备如下功能：
class tuple(object):
"""
tuple() -> empty tuple
tuple(iterable) -> tuple initialized from iterable's items If the argument is a tuple, the return value is the same object.
"""
def count(self, value): # real signature unknown; restored from __doc__
""" T.count(value) -> integer -- return number of occurrences of value """
return 0 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
"""
T.index(value, [start, [stop]]) -> integer -- return first index of value.
Raises ValueError if the value is not present.
"""
return 0 def __add__(self, y): # real signature unknown; restored from __doc__
""" x.__add__(y) <==> x+y """
pass def __contains__(self, y): # real signature unknown; restored from __doc__
""" x.__contains__(y) <==> y in x """
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y): # real signature unknown; restored from __doc__
""" x.__getitem__(y) <==> x[y] """
pass def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass def __getslice__(self, i, j): # real signature unknown; restored from __doc__
"""
x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported.
"""
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __hash__(self): # real signature unknown; restored from __doc__
""" x.__hash__() <==> hash(x) """
pass def __init__(self, seq=()): # known special case of tuple.__init__
"""
tuple() -> empty tuple
tuple(iterable) -> tuple initialized from iterable's items If the argument is a tuple, the return value is the same object.
# (copied from class doc)
"""
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass def __mul__(self, n): # real signature unknown; restored from __doc__
""" x.__mul__(n) <==> x*n """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __rmul__(self, n): # real signature unknown; restored from __doc__
""" x.__rmul__(n) <==> n*x """
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" T.__sizeof__() -- size of T in memory, in bytes """
pass
tuple
七、字典
name={
395159623:{'age':29,'shengao':185,'sex':"man"},
917643002:{'age':30,'shengao':160,'sex':"woman"}
}
print (name.get(395159623).get('age'))
如：{'name': 'wupeiqi', 'age': 18} 、{'host': '2.2.2.2', 'port': 80]}
ps：循环时，默认循环key
每个字典都具备如下功能：字典的key是不可以重复的，他是无位置的，无序的。
什么可以当做字典的key呢？
数字，字符串，类的实例 不可以变的，时间也行
ipmort datatime
a = datatime.datatime.now()
如何判断是不是一个字典？ type(name_dic) is dict
大的数据循环字典，应该这样：
for k in b:
print k,b[k]
这样比较好，因为正常的循环字典会一次性的把字典中的所有值都提出来，放到内存中，比较耗内存。
copy: 浅copy
D.copy() #拷贝字典 ，他是一个浅的拷贝，在副本中替换值的时候，原始字段不受影响，但是修改了某个值时（原地修改，不是替换）原始字典也会改变（我理解的还是第一层的对象是不会发生变化的，而里边的其他层就会随之变化），对应的还有深拷贝，我们得借助模块了。data4 = copy.deepcopy(data)，就是把所有层级都copy了, 也就是完全独立了。
x = {'username':'admin','machines':['foo','bar','baz']}
y = x.copy()
y['username']='mih'
y['machines'].remove('bar')
print x
print y
{'username': 'admin', 'machines': ['foo', 'baz']}
{'username': 'mih', 'machines': ['foo', 'baz']
这个例子是这样解释的，y copy了x ,其实是在内存中第一层数据是独立，尔第二层数据其实用的是一份，其实就指针指向了同一块内存地址，这样我改第一层数据的时候，x y是不会同时变化的，而我改第二层数据的时候，他们其实用的是同一块地址，那么数据就会一同改变。而deepcopy是产生了一份完完全全独立的数据。
class dict(object):
"""
dict() -> new empty dictionary
dict(mapping) -> new dictionary initialized from a mapping object's
(key, value) pairs
dict(iterable) -> new dictionary initialized as if via:
d = {}
for k, v in iterable:
d[k] = v
dict(**kwargs) -> new dictionary initialized with the name=value pairs
in the keyword argument list. For example: dict(one=1, two=2)
""" def clear(self): # real signature unknown; restored from __doc__
""" 清除内容 """
""" D.clear() -> None. Remove all items from D. """
pass def copy(self): # real signature unknown; restored from __doc__
""" 浅拷贝 """
""" D.copy() -> a shallow copy of D """
pass @staticmethod # known case
def fromkeys(S, v=None): # real signature unknown; restored from __doc__
"""
dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v.
v defaults to None.
"""
pass
a.formkeys([1,2,3],’t’)
{1:’t’,2:’t’,3:’t’}
def get(self, k, d=None): # real signature unknown; restored from __doc__
""" 根据key获取值，d是默认值 """
""" D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None. """
pass
dic = {‘k1’:1234}
disc[‘k1’]
dic.get(‘k2’)这样也可以获取元素，没有这个值，也不会报错。
dic.get(‘k2’,’ok’)
ok
def has_key(self, k): # real signature unknown; restored from __doc__
""" 是否有key """
""" D.has_key(k) -> True if D has a key k, else False """
return False def items(self): # real signature unknown; restored from __doc__
""" 所有项的列表形式 """
""" D.items() -> list of D's (key, value) pairs, as 2-tuples """
return [] def iteritems(self): # real signature unknown; restored from __doc__
""" 项可迭代 """
""" D.iteritems() -> an iterator over the (key, value) items of D """
pass def iterkeys(self): # real signature unknown; restored from __doc__
""" key可迭代 """
""" D.iterkeys() -> an iterator over the keys of D """
pass def itervalues(self): # real signature unknown; restored from __doc__
""" value可迭代 """
""" D.itervalues() -> an iterator over the values of D """
pass def keys(self): # real signature unknown; restored from __doc__
""" 所有的key列表 """
""" D.keys() -> list of D's keys """
return [] def pop(self, k, d=None): # real signature unknown; restored from __doc__
""" 获取并在字典中移除 ，指定key"""还可以这样 del b[1]
"""
D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
If key is not found, d is returned if given, otherwise KeyError is raised
"""
pass def popitem(self): # real signature unknown; restored from __doc__
""" 获取并在字典中移除 """---删掉内存中的数据因为字典是无序，所以不好控制。
"""
D.popitem() -> (k, v), remove and return some (key, value) pair as a
2-tuple; but raise KeyError if D is empty.
"""
pass def setdefault(self, k, d=None): # real signature unknown; restored from __doc__
""" 如果key不存在，则创建，如果存在，则返回已存在的值且不修改 """
""" D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """
pass def update(self, E=None, **F): # known special case of dict.update
""" 更新
{'name':'alex', 'age': 18000}
[('name','sbsbsb'),]
"""
""" 把两个字典中的元素整合到一个字典中，c.update(d) 循环d，把d中的付给c
D.update([E, ]**F) -> None. Update D from dict/iterable E and F.
If E present and has a .keys() method, does: for k in E: D[k] = E[k]
If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v
In either case, this is followed by: for k in F: D[k] = F[k]
"""
pass def values(self): # real signature unknown; restored from __doc__
""" 所有的值 """
""" D.values() -> list of D's values """
return [] def viewitems(self): # real signature unknown; restored from __doc__
""" 所有项，只是将内容保存至view对象中 """
""" D.viewitems() -> a set-like object providing a view on D's items """
pass def viewkeys(self): # real signature unknown; restored from __doc__
""" D.viewkeys() -> a set-like object providing a view on D's keys """
pass def viewvalues(self): # real signature unknown; restored from __doc__
""" D.viewvalues() -> an object providing a view on D's values """
pass def __cmp__(self, y): # real signature unknown; restored from __doc__
""" x.__cmp__(y) <==> cmp(x,y) """
pass def __contains__(self, k): # real signature unknown; restored from __doc__
""" D.__contains__(k) -> True if D has a key k, else False """
return False def __delitem__(self, y): # real signature unknown; restored from __doc__
""" x.__delitem__(y) <==> del x[y] """
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y): # real signature unknown; restored from __doc__
""" x.__getitem__(y) <==> x[y] """
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __init__(self, seq=None, **kwargs): # known special case of dict.__init__
"""
dict() -> new empty dictionary
dict(mapping) -> new dictionary initialized from a mapping object's
(key, value) pairs
dict(iterable) -> new dictionary initialized as if via:
d = {}
for k, v in iterable:
d[k] = v
dict(**kwargs) -> new dictionary initialized with the name=value pairs
in the keyword argument list. For example: dict(one=1, two=2)
# (copied from class doc)
"""
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__
""" x.__setitem__(i, y) <==> x[i]=y """
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" D.__sizeof__() -> size of D in memory, in bytes """
pass __hash__ = None
dict
|
1
2
3
|
练习：元素分类有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。即： {'k1': 大于66 , 'k2': 小于66} |
方法1
li = [11,22,33,44,55,66,77,88,99,90]
dic = {'k1':[],'k2':[]}
for item in li:
if item>66:
dic['k2'].append(item)
else:
dic['k1'].append(item)
方法2：
li = [11,22,33,44,55,66,77,88,99,90]
dic = {}
for item in li:
if item > 66:
if 'k2' in dic.keys():
dic['k2'].append(item)
else:
#创建只有一项元素的列表
dic['k2'] = [item,]
else:
if item > 66:
if 'k2' in dic.keys():
dic['k2'].append(item)
else:
dic['k2'] = [item,]
方法
alex|123|1
sun|123|1
bo|123|1
变成这样的字典
dic = {
'alex':[123,1],
'bo':[123,1],
'sun':[123,1],
} dic = {}
#打开文件，读取文件
obj = file('log','r')
line_list = obj.readlines()
obj.close()
for line in line_list:
line = line.strip() #去掉换行和空格
ele_list = line.split('|') #分割['alex','123','1']
dic[ele_list[0]] = ele_list[1:]
文件格式化
字典的操作
##key定义规则,1,不可变:数字,字符串,元组 (可以用作key)
2 可变的:列表,字典
##value定义规则:任意类型
增(字典是无序的)
dic = {'name':'sun','age':29}
print (dic)
dic['sex']='man'
print(dic)
删
del dic['name']
print(dic)
改(只能改vlaue,key不能改)
dic = {'name':'sun','age':29}
print (dic)
dic['name']='zhaoyue'
print(dic)
查
name={
395159623:{'age':29,'shengao':185,'sex':"man"},
917643002:{'age':30,'shengao':160,'sex':"woman"}
}
print (name.get(395159623).get('age'))
字典的循环方式
dis={'name':'sunbo','age':18}###多用这种方式
for key in dis:
print(key,dis[key])
for k,v in dis.items():###items得先把字典转化成列表,效率不高.
print(k,v)
八、set集合
重要功能：去重 比较
set是一个无序且不重复的元素集合
a = range(5,10)
b = range(7,12)
c = set(a)
d = set(b)
c & d 交集
c|d 并集
c ^d 取反
c – d c里面有d里面没有的
===========================
a & b #求交集 a.intersection(b)
a | b #求并集 a.union(b)
a – b # 求差集 a.difference(b)
a ^ b #求对称差集 a.symmetric_difference(b)
a.issubset(b) #a 是b 的子集
a.issuperset(b) # a 是否包含b
============================
class set(object):
"""
set() -> new empty set object
set(iterable) -> new set object Build an unordered collection of unique elements.
"""
def add(self, *args, **kwargs): # real signature unknown
""" 添加 """
"""
Add an element to a set. This has no effect if the element is already present.
"""
pass def clear(self, *args, **kwargs): # real signature unknown
""" Remove all elements from this set. """
pass def copy(self, *args, **kwargs): # real signature unknown
""" Return a shallow copy of a set. """
pass def difference(self, *args, **kwargs): # real signature unknown
"""
Return the difference of two or more sets as a new set. (i.e. all elements that are in this set but not the others.)
"""
pass def difference_update(self, *args, **kwargs): # real signature unknown
""" 删除当前set中的所有包含在 new set 里的元素 """
""" Remove all elements of another set from this set. """
pass def discard(self, *args, **kwargs): # real signature unknown
""" 移除元素 """
"""
Remove an element from a set if it is a member. If the element is not a member, do nothing.
"""
pass def intersection(self, *args, **kwargs): # real signature unknown
""" 取交集，新创建一个set """
"""
Return the intersection of two or more sets as a new set. (i.e. elements that are common to all of the sets.)
"""
pass def intersection_update(self, *args, **kwargs): # real signature unknown
""" 取交集，修改原来set """
""" Update a set with the intersection of itself and another. """
pass def isdisjoint(self, *args, **kwargs): # real signature unknown
""" 如果没有交集，返回true """
""" Return True if two sets have a null intersection. """
pass def issubset(self, *args, **kwargs): # real signature unknown
""" 是否是子集 """
""" Report whether another set contains this set. """
pass def issuperset(self, *args, **kwargs): # real signature unknown
""" 是否是父集 """
""" Report whether this set contains another set. """
pass def pop(self, *args, **kwargs): # real signature unknown
""" 移除 """
"""
Remove and return an arbitrary set element.
Raises KeyError if the set is empty.
"""
pass def remove(self, *args, **kwargs): # real signature unknown
""" 移除 """
"""
Remove an element from a set; it must be a member. If the element is not a member, raise a KeyError.
"""
pass def symmetric_difference(self, *args, **kwargs): # real signature unknown
""" 差集，创建新对象"""
"""
Return the symmetric difference of two sets as a new set. (i.e. all elements that are in exactly one of the sets.)
"""
pass def symmetric_difference_update(self, *args, **kwargs): # real signature unknown
""" 差集，改变原来 """
""" Update a set with the symmetric difference of itself and another. """
pass def union(self, *args, **kwargs): # real signature unknown
""" 并集 """
"""
Return the union of sets as a new set. (i.e. all elements that are in either set.)
"""
pass def update(self, *args, **kwargs): # real signature unknown
""" 更新 """
""" Update a set with the union of itself and others. """
pass def __and__(self, y): # real signature unknown; restored from __doc__
""" x.__and__(y) <==> x&y """
pass def __cmp__(self, y): # real signature unknown; restored from __doc__
""" x.__cmp__(y) <==> cmp(x,y) """
pass def __contains__(self, y): # real signature unknown; restored from __doc__
""" x.__contains__(y) <==> y in x. """
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __iand__(self, y): # real signature unknown; restored from __doc__
""" x.__iand__(y) <==> x&=y """
pass def __init__(self, seq=()): # known special case of set.__init__
"""
set() -> new empty set object
set(iterable) -> new set object Build an unordered collection of unique elements.
# (copied from class doc)
"""
pass def __ior__(self, y): # real signature unknown; restored from __doc__
""" x.__ior__(y) <==> x|=y """
pass def __isub__(self, y): # real signature unknown; restored from __doc__
""" x.__isub__(y) <==> x-=y """
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __ixor__(self, y): # real signature unknown; restored from __doc__
""" x.__ixor__(y) <==> x^=y """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __or__(self, y): # real signature unknown; restored from __doc__
""" x.__or__(y) <==> x|y """
pass def __rand__(self, y): # real signature unknown; restored from __doc__
""" x.__rand__(y) <==> y&x """
pass def __reduce__(self, *args, **kwargs): # real signature unknown
""" Return state information for pickling. """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __ror__(self, y): # real signature unknown; restored from __doc__
""" x.__ror__(y) <==> y|x """
pass def __rsub__(self, y): # real signature unknown; restored from __doc__
""" x.__rsub__(y) <==> y-x """
pass def __rxor__(self, y): # real signature unknown; restored from __doc__
""" x.__rxor__(y) <==> y^x """
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" S.__sizeof__() -> size of S in memory, in bytes """
pass def __sub__(self, y): # real signature unknown; restored from __doc__
""" x.__sub__(y) <==> x-y """
pass def __xor__(self, y): # real signature unknown; restored from __doc__
""" x.__xor__(y) <==> x^y """
pass __hash__ = None
set
练习：寻找差异
# 数据库中原有old_dict = { "#1":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 }, "#2":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 } "#3":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 }}# cmdb 新汇报的数据new_dict = { "#1":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 800 }, "#3":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 } "#4":{ 'hostname':c2, 'cpu_count': 2, 'mem_capicity': 80 }}需要删除：？需要新建：？需要更新：？ 注意：无需考虑内部元素是否改变，只要原来存在，新汇报也存在，就是需要更新old_set = set(old_dict.keys())
update_list = list(old_set.intersection(new_dict.keys())) new_list = []
del_list = [] for i in new_dict.keys():
if i not in update_list:
new_list.append(i) for i in old_dict.keys():
if i not in update_list:
del_list.append(i) print update_list,new_list,del_list
九、collection系列
1、计数器（counter）
Counter是对字典类型的补充，用于追踪值的出现次数。
ps：具备字典的所有功能 + 自己的功能
引入collections模块
import collections
collections.Counter('aaabbcc')
c1 = collections.Counter('aabb')
c2 = collections.Counter('aacc')
c1.update(c2)
c = Counter('abcdeabcdabcaba')
print c
输出：Counter({'a': 5, 'b': 4, 'c': 3, 'd': 2, 'e': 1}
########################################################################
### Counter
######################################################################## class Counter(dict): #当前扩展的字典
'''Dict subclass for counting hashable items. Sometimes called a bag
or multiset. Elements are stored as dictionary keys and their counts
are stored as dictionary values. >>> c = Counter('abcdeabcdabcaba') # count elements from a string >>> c.most_common(3) # three most common elements后面的参数的意思是至少出现3次
[('a', 5), ('b', 4), ('c', 3)]
>>> sorted(c) # list all unique elements
['a', 'b', 'c', 'd', 'e']
>>> ''.join(sorted(c.elements())) # list elements with repetitions
'aaaaabbbbcccdde'
>>> sum(c.values()) # total of all counts >>> c['a'] # count of letter 'a'
>>> for elem in 'shazam': # update counts from an iterable
... c[elem] += 1 # by adding 1 to each element's count
>>> c['a'] # now there are seven 'a'
>>> del c['b'] # remove all 'b'
>>> c['b'] # now there are zero 'b' >>> d = Counter('simsalabim') # make another counter
>>> c.update(d) # add in the second counter把d加入到c中。
>>> c['a'] # now there are nine 'a' >>> c.clear() # empty the counter
>>> c
Counter() Note: If a count is set to zero or reduced to zero, it will remain
in the counter until the entry is deleted or the counter is cleared: >>> c = Counter('aaabbc')
>>> c['b'] -= 2 # reduce the count of 'b' by two
>>> c.most_common() # 'b' is still in, but its count is zero
[('a', 3), ('c', 1), ('b', 0)] '''
# References:
# http://en.wikipedia.org/wiki/Multiset
# http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html
# http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm
# http://code.activestate.com/recipes/259174/
# Knuth, TAOCP Vol. II section 4.6.3 def __init__(self, iterable=None, **kwds):
'''Create a new, empty Counter object. And if given, count elements
from an input iterable. Or, initialize the count from another mapping
of elements to their counts. >>> c = Counter() # a new, empty counter
>>> c = Counter('gallahad') # a new counter from an iterable
>>> c = Counter({'a': 4, 'b': 2}) # a new counter from a mapping
>>> c = Counter(a=4, b=2) # a new counter from keyword args '''
super(Counter, self).__init__()
self.update(iterable, **kwds) def __missing__(self, key):
""" 对于不存在的元素，返回计数器为0 """
'The count of elements not in the Counter is zero.'
# Needed so that self[missing_item] does not raise KeyError
return 0 def most_common(self, n=None):
""" 列出前几位的元素"""
'''List the n most common elements and their counts from the most
common to the least. If n is None, then list all element counts. >>> Counter('abcdeabcdabcaba').most_common(3)
[('a', 5), ('b', 4), ('c', 3)] '''
# Emulate Bag.sortedByCount from Smalltalk
if n is None:
return sorted(self.iteritems(), key=_itemgetter(1), reverse=True)
return _heapq.nlargest(n, self.iteritems(), key=_itemgetter(1)) def elements(self):
""" 计数器中的所有元素，注：此处非所有元素集合，而是包含所有元素集合的迭代器 """
'''Iterator over elements repeating each as many times as its count. >>> c = Counter('ABCABC')
>>> sorted(c.elements())
['A', 'A', 'B', 'B', 'C', 'C'] # Knuth's example for prime factors of 1836: 2**2 * 3**3 * 17**1
>>> prime_factors = Counter({2: 2, 3: 3, 17: 1})
>>> product = 1
>>> for factor in prime_factors.elements(): # loop over factors
... product *= factor # and multiply them
>>> product Note, if an element's count has been set to zero or is a negative
number, elements() will ignore it. '''
# Emulate Bag.do from Smalltalk and Multiset.begin from C++.
return _chain.from_iterable(_starmap(_repeat, self.iteritems())) # Override dict methods where necessary @classmethod
def fromkeys(cls, iterable, v=None):
# There is no equivalent method for counters because setting v=1
# means that no element can have a count greater than one.
raise NotImplementedError(
'Counter.fromkeys() is undefined. Use Counter(iterable) instead.') def update(self, iterable=None, **kwds):
""" 更新计数器，其实就是增加；如果原来没有，则新建，如果有则加一 """
'''Like dict.update() but add counts instead of replacing them. Source can be an iterable, a dictionary, or another Counter instance. >>> c = Counter('which')
>>> c.update('witch') # add elements from another iterable
>>> d = Counter('watch')
>>> c.update(d) # add elements from another counter
>>> c['h'] # four 'h' in which, witch, and watch '''
# The regular dict.update() operation makes no sense here because the
# replace behavior results in the some of original untouched counts
# being mixed-in with all of the other counts for a mismash that
# doesn't have a straight-forward interpretation in most counting
# contexts. Instead, we implement straight-addition. Both the inputs
# and outputs are allowed to contain zero and negative counts. if iterable is not None:
if isinstance(iterable, Mapping):
if self:
self_get = self.get
for elem, count in iterable.iteritems():
self[elem] = self_get(elem, 0) + count
else:
super(Counter, self).update(iterable) # fast path when counter is empty
else:
self_get = self.get
for elem in iterable:
self[elem] = self_get(elem, 0) + 1
if kwds:
self.update(kwds) def subtract(self, iterable=None, **kwds):
""" 相减，原来的计数器中的每一个元素的数量减去后添加的元素的数量 """
'''Like dict.update() but subtracts counts instead of replacing them.
Counts can be reduced below zero. Both the inputs and outputs are
allowed to contain zero and negative counts. Source can be an iterable, a dictionary, or another Counter instance. >>> c = Counter('which')
>>> c.subtract('witch') # subtract elements from another iterable
>>> c.subtract(Counter('watch')) # subtract elements from another counter
>>> c['h'] # 2 in which, minus 1 in witch, minus 1 in watch
>>> c['w'] # 1 in which, minus 1 in witch, minus 1 in watch
-1 '''
if iterable is not None:
self_get = self.get
if isinstance(iterable, Mapping):
for elem, count in iterable.items():
self[elem] = self_get(elem, 0) - count
else:
for elem in iterable:
self[elem] = self_get(elem, 0) - 1
if kwds:
self.subtract(kwds) def copy(self):
""" 拷贝 """
'Return a shallow copy.'
return self.__class__(self) def __reduce__(self):
""" 返回一个元组（类型，元组） """
return self.__class__, (dict(self),) def __delitem__(self, elem):
""" 删除元素 """
'Like dict.__delitem__() but does not raise KeyError for missing values.'
if elem in self:
super(Counter, self).__delitem__(elem) def __repr__(self):
if not self:
return '%s()' % self.__class__.__name__
items = ', '.join(map('%r: %r'.__mod__, self.most_common()))
return '%s({%s})' % (self.__class__.__name__, items) # Multiset-style mathematical operations discussed in:
# Knuth TAOCP Volume II section 4.6.3 exercise 19
# and at http://en.wikipedia.org/wiki/Multiset
#
# Outputs guaranteed to only include positive counts.
#
# To strip negative and zero counts, add-in an empty counter:
# c += Counter() def __add__(self, other):
'''Add counts from two counters. >>> Counter('abbb') + Counter('bcc')
Counter({'b': 4, 'c': 2, 'a': 1}) '''
if not isinstance(other, Counter):
return NotImplemented
result = Counter()
for elem, count in self.items():
newcount = count + other[elem]
if newcount > 0:
result[elem] = newcount
for elem, count in other.items():
if elem not in self and count > 0:
result[elem] = count
return result def __sub__(self, other):
''' Subtract count, but keep only results with positive counts. >>> Counter('abbbc') - Counter('bccd')
Counter({'b': 2, 'a': 1}) '''
if not isinstance(other, Counter):
return NotImplemented
result = Counter()
for elem, count in self.items():
newcount = count - other[elem]
if newcount > 0:
result[elem] = newcount
for elem, count in other.items():
if elem not in self and count < 0:
result[elem] = 0 - count
return result def __or__(self, other):
'''Union is the maximum of value in either of the input counters. >>> Counter('abbb') | Counter('bcc')
Counter({'b': 3, 'c': 2, 'a': 1}) '''
if not isinstance(other, Counter):
return NotImplemented
result = Counter()
for elem, count in self.items():
other_count = other[elem]
newcount = other_count if count < other_count else count
if newcount > 0:
result[elem] = newcount
for elem, count in other.items():
if elem not in self and count > 0:
result[elem] = count
return result def __and__(self, other):
''' Intersection is the minimum of corresponding counts. >>> Counter('abbb') & Counter('bcc')
Counter({'b': 1}) '''
if not isinstance(other, Counter):
return NotImplemented
result = Counter()
for elem, count in self.items():
other_count = other[elem]
newcount = count if count < other_count else other_count
if newcount > 0:
result[elem] = newcount
return result Counter
Counter
2、有序字典(orderedDict )
orderdDict是对字典类型的补充，他记住了字典元素添加的顺序
o1 = collections.OrderedDict()
o1['k1'] = 1
o1['k2'] = 2
o1['k3'] = 3
有序字典其实内部有一个列表，等以后去数据的时候，就会根据类表的顺序去取得。
class OrderedDict(dict):
'Dictionary that remembers insertion order'
# An inherited dict maps keys to values.
# The inherited dict provides __getitem__, __len__, __contains__, and get.
# The remaining methods are order-aware.
# Big-O running times for all methods are the same as regular dictionaries. # The internal self.__map dict maps keys to links in a doubly linked list.
# The circular doubly linked list starts and ends with a sentinel element.
# The sentinel element never gets deleted (this simplifies the algorithm).
# Each link is stored as a list of length three: [PREV, NEXT, KEY]. def __init__(self, *args, **kwds):
'''Initialize an ordered dictionary. The signature is the same as
regular dictionaries, but keyword arguments are not recommended because
their insertion order is arbitrary. '''
if len(args) > 1:
raise TypeError('expected at most 1 arguments, got %d' % len(args))
try:
self.__root
except AttributeError:
self.__root = root = [] # sentinel node
root[:] = [root, root, None]
self.__map = {}
self.__update(*args, **kwds) def __setitem__(self, key, value, dict_setitem=dict.__setitem__):
'od.__setitem__(i, y) <==> od[i]=y'
# Setting a new item creates a new link at the end of the linked list,
# and the inherited dictionary is updated with the new key/value pair.
if key not in self:
root = self.__root
last = root[0]
last[1] = root[0] = self.__map[key] = [last, root, key]
return dict_setitem(self, key, value) def __delitem__(self, key, dict_delitem=dict.__delitem__):
'od.__delitem__(y) <==> del od[y]'
# Deleting an existing item uses self.__map to find the link which gets
# removed by updating the links in the predecessor and successor nodes.
dict_delitem(self, key)
link_prev, link_next, _ = self.__map.pop(key)
link_prev[1] = link_next # update link_prev[NEXT]
link_next[0] = link_prev # update link_next[PREV] def __iter__(self):
'od.__iter__() <==> iter(od)'
# Traverse the linked list in order.
root = self.__root
curr = root[1] # start at the first node
while curr is not root:
yield curr[2] # yield the curr[KEY]
curr = curr[1] # move to next node def __reversed__(self):
'od.__reversed__() <==> reversed(od)'
# Traverse the linked list in reverse order.
root = self.__root
curr = root[0] # start at the last node
while curr is not root:
yield curr[2] # yield the curr[KEY]
curr = curr[0] # move to previous node def clear(self):
'od.clear() -> None. Remove all items from od.'
root = self.__root
root[:] = [root, root, None]
self.__map.clear()
dict.clear(self) # -- the following methods do not depend on the internal structure -- def keys(self):
'od.keys() -> list of keys in od'
return list(self) def values(self):
'od.values() -> list of values in od'
return [self[key] for key in self] def items(self):
'od.items() -> list of (key, value) pairs in od'
return [(key, self[key]) for key in self] def iterkeys(self):
'od.iterkeys() -> an iterator over the keys in od'
return iter(self) def itervalues(self):
'od.itervalues -> an iterator over the values in od'
for k in self:
yield self[k] def iteritems(self):
'od.iteritems -> an iterator over the (key, value) pairs in od'
for k in self:
yield (k, self[k]) update = MutableMapping.update __update = update # let subclasses override update without breaking __init__ __marker = object() def pop(self, key, default=__marker):
'''od.pop(k[,d]) -> v, remove specified key and return the corresponding
value. If key is not found, d is returned if given, otherwise KeyError
is raised. '''
if key in self:
result = self[key]
del self[key]
return result
if default is self.__marker:
raise KeyError(key)
return default def setdefault(self, key, default=None):
'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od'
if key in self:
return self[key]
self[key] = default
return default def popitem(self, last=True):
'''od.popitem() -> (k, v), return and remove a (key, value) pair.
Pairs are returned in LIFO order if last is true or FIFO order if false. '''
if not self:
raise KeyError('dictionary is empty')
key = next(reversed(self) if last else iter(self))
value = self.pop(key)
return key, value def __repr__(self, _repr_running={}):
'od.__repr__() <==> repr(od)'
call_key = id(self), _get_ident()
if call_key in _repr_running:
return '...'
_repr_running[call_key] = 1
try:
if not self:
return '%s()' % (self.__class__.__name__,)
return '%s(%r)' % (self.__class__.__name__, self.items())
finally:
del _repr_running[call_key] def __reduce__(self):
'Return state information for pickling'
items = [[k, self[k]] for k in self]
inst_dict = vars(self).copy()
for k in vars(OrderedDict()):
inst_dict.pop(k, None)
if inst_dict:
return (self.__class__, (items,), inst_dict)
return self.__class__, (items,) def copy(self):
'od.copy() -> a shallow copy of od'
return self.__class__(self) @classmethod
def fromkeys(cls, iterable, value=None):
'''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S.
If not specified, the value defaults to None. '''
self = cls()
for key in iterable:
self[key] = value
return self def __eq__(self, other):
'''od.__eq__(y) <==> od==y. Comparison to another OD is order-sensitive
while comparison to a regular mapping is order-insensitive. '''
if isinstance(other, OrderedDict):
return dict.__eq__(self, other) and all(_imap(_eq, self, other))
return dict.__eq__(self, other) def __ne__(self, other):
'od.__ne__(y) <==> od!=y'
return not self == other # -- the following methods support python 3.x style dictionary views -- def viewkeys(self):
"od.viewkeys() -> a set-like object providing a view on od's keys"
return KeysView(self) def viewvalues(self):
"od.viewvalues() -> an object providing a view on od's values"
return ValuesView(self) def viewitems(self):
"od.viewitems() -> a set-like object providing a view on od's items"
return ItemsView(self)
OrderedDict
3、默认字典(defaultdict) ---默认所有的字典的value都为空的列表
也就是为你字典的值设置一个默认类型
my_dict = defaultdict(dict)----也可以自己设置字典里的values时字典
学前需求：
有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。
即： {'k1': 大于66 , 'k2': 小于66}
values = [11, 22, 33,44,55,66,77,88,99,90]
my_dict = {}
for value in values:
if value>66:
if my_dict.has_key('k1'):
my_dict['k1'].append(value)
else:
my_dict['k1'] = [value]
else:
if my_dict.has_key('k2'):
my_dict['k2'].append(value)
else:
my_dict['k2'] = [value]
原生字典解决方法
from collections import defaultdict values = [11, 22, 33,44,55,66,77,88,99,90] my_dict = defaultdict(list) for value in values:
if value>66:
my_dict['k1'].append(value)
else:
my_dict['k2'].append(value)
defaultdict字典解决方法
defaultdict是对字典的类型的补充，他默认给字典的值设置了一个类型。
class defaultdict(dict):
"""
defaultdict(default_factory[, ...]) --> dict with default factory The default factory is called without arguments to produce
a new value when a key is not present, in __getitem__ only.
A defaultdict compares equal to a dict with the same items.
All remaining arguments are treated the same as if they were
passed to the dict constructor, including keyword arguments.
"""
def copy(self): # real signature unknown; restored from __doc__
""" D.copy() -> a shallow copy of D. """
pass def __copy__(self, *args, **kwargs): # real signature unknown
""" D.copy() -> a shallow copy of D. """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __init__(self, default_factory=None, **kwargs): # known case of _collections.defaultdict.__init__
"""
defaultdict(default_factory[, ...]) --> dict with default factory The default factory is called without arguments to produce
a new value when a key is not present, in __getitem__ only.
A defaultdict compares equal to a dict with the same items.
All remaining arguments are treated the same as if they were
passed to the dict constructor, including keyword arguments. # (copied from class doc)
"""
pass def __missing__(self, key): # real signature unknown; restored from __doc__
"""
__missing__(key) # Called by __getitem__ for missing key; pseudo-code:
if self.default_factory is None: raise KeyError((key,))
self[key] = value = self.default_factory()
return value
"""
pass def __reduce__(self, *args, **kwargs): # real signature unknown
""" Return state information for pickling. """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass default_factory = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""Factory for default value called by __missing__()."""
defaultdict
4、可命名元组(namedtuple)
根据nametuple可以创建一个包含tuple所有功能以及其他功能的类型。
import collections
Mytuple = collections.namedtuple('Mytuple',['x', 'y', 'z'])
如何使用：
1 首先要创建类：创建我自己的类，这个类是对我原生tuple
Mytuple = collections.namedtuple('Mytuple',['x', 'y', 'z'])
2 根据类创建对象 new = Mytuple(1,2)
3 使用对象 new =====Mytuple(x=1,y=2) n.x n.y
class Mytuple(__builtin__.tuple)---对tuple进行扩展，也叫作基础
| Mytuple(x, y)
|
| Method resolution order:
| Mytuple
| __builtin__.tuple
| __builtin__.object
|
| Methods defined here:
|
| __getnewargs__(self)
| Return self as a plain tuple. Used by copy and pickle.
|
| __getstate__(self)
| Exclude the OrderedDict from pickling
|
| __repr__(self)
| Return a nicely formatted representation string
|
| _asdict(self)
| Return a new OrderedDict which maps field names to their values
|
| _replace(_self, **kwds)
| Return a new Mytuple object replacing specified fields with new values
|
| ----------------------------------------------------------------------
| Class methods defined here:
|
| _make(cls, iterable, new=<built-in method __new__ of type object>, len=<built-in function len>) from __builtin__.type
| Make a new Mytuple object from a sequence or iterable
|
| ----------------------------------------------------------------------
| Static methods defined here:
|
| __new__(_cls, x, y)
| Create new instance of Mytuple(x, y)
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| __dict__
| Return a new OrderedDict which maps field names to their values
|
| x
| Alias for field number 0
|
| y
| Alias for field number 1
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| _fields = ('x', 'y')
|
| ----------------------------------------------------------------------
| Methods inherited from __builtin__.tuple:
|
| __add__(...)
| x.__add__(y) <==> x+y
|
| __contains__(...)
| x.__contains__(y) <==> y in x
|
| __eq__(...)
| x.__eq__(y) <==> x==y
|
| __ge__(...)
| x.__ge__(y) <==> x>=y
|
| __getattribute__(...)
| x.__getattribute__('name') <==> x.name
|
| __getitem__(...)
| x.__getitem__(y) <==> x[y]
|
| __getslice__(...)
| x.__getslice__(i, j) <==> x[i:j]
|
| Use of negative indices is not supported.
|
| __gt__(...)
| x.__gt__(y) <==> x>y
|
| __hash__(...)
| x.__hash__() <==> hash(x)
|
| __iter__(...)
| x.__iter__() <==> iter(x)
|
| __le__(...)
| x.__le__(y) <==> x<=y
|
| __len__(...)
| x.__len__() <==> len(x)
|
| __lt__(...)
| x.__lt__(y) <==> x<y
|
| __mul__(...)
| x.__mul__(n) <==> x*n
|
| __ne__(...)
| x.__ne__(y) <==> x!=y
|
| __rmul__(...)
| x.__rmul__(n) <==> n*x
|
| __sizeof__(...)
| T.__sizeof__() -- size of T in memory, in bytes
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present. Mytuple
Mytuple
5、双向队列(deque)---任意从两边插入和取走元素
一个线程安全的双向队列：类似于加一个锁，防止冲突。
class deque(object):
"""
deque([iterable[, maxlen]]) --> deque object Build an ordered collection with optimized access from its endpoints.
"""
def append(self, *args, **kwargs): # real signature unknown
""" Add an element to the right side of the deque. """
pass def appendleft(self, *args, **kwargs): # real signature unknown
""" Add an element to the left side of the deque. """
pass def clear(self, *args, **kwargs): # real signature unknown
""" Remove all elements from the deque. """
pass def count(self, value): # real signature unknown; restored from __doc__
""" D.count(value) -> integer -- return number of occurrences of value """
return 0 def extend(self, *args, **kwargs): # real signature unknown
""" Extend the right side of the deque with elements from the iterable """
pass def extendleft(self, *args, **kwargs): # real signature unknown
""" Extend the left side of the deque with elements from the iterable """
pass def pop(self, *args, **kwargs): # real signature unknown
""" Remove and return the rightmost element. """
pass ###在队列中取最右边的值，并在队列中删除这个值 def popleft(self, *args, **kwargs): # real signature unknown
""" Remove and return the leftmost element. """
pass def remove(self, value): # real signature unknown; restored from __doc__
""" D.remove(value) -- remove first occurrence of value. """
pass def reverse(self): # real signature unknown; restored from __doc__
""" D.reverse() -- reverse *IN PLACE* """
pass def rotate(self, *args, **kwargs): # real signature unknown
""" Rotate the deque n steps to the right (default n=1). If n is negative, rotates left. """
pass def __copy__(self, *args, **kwargs): # real signature unknown
""" Return a shallow copy of a deque. """
pass def __delitem__(self, y): # real signature unknown; restored from __doc__
""" x.__delitem__(y) <==> del x[y] """
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y): # real signature unknown; restored from __doc__
""" x.__getitem__(y) <==> x[y] """
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __iadd__(self, y): # real signature unknown; restored from __doc__
""" x.__iadd__(y) <==> x+=y """
pass def __init__(self, iterable=(), maxlen=None): # known case of _collections.deque.__init__
"""
deque([iterable[, maxlen]]) --> deque object Build an ordered collection with optimized access from its endpoints.
# (copied from class doc)
"""
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __reduce__(self, *args, **kwargs): # real signature unknown
""" Return state information for pickling. """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __reversed__(self): # real signature unknown; restored from __doc__
""" D.__reversed__() -- return a reverse iterator over the deque """
pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__
""" x.__setitem__(i, y) <==> x[i]=y """
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" D.__sizeof__() -- size of D in memory, in bytes """
pass maxlen = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""maximum size of a deque or None if unbounded""" __hash__ = None
deque
注：既然有双向队列，也有单项队列（先进先出 FIFO ）
单项队列，在queue这个类中
引用： import queue
创建 q = Queue.Queue(10) #队列长度10
存入： q.put(1)
提取：q.get()
class Queue:
"""Create a queue object with a given maximum size. If maxsize is <= 0, the queue size is infinite.
"""
def __init__(self, maxsize=0):
self.maxsize = maxsize
self._init(maxsize)
# mutex must be held whenever the queue is mutating. All methods
# that acquire mutex must release it before returning. mutex
# is shared between the three conditions, so acquiring and
# releasing the conditions also acquires and releases mutex.
self.mutex = _threading.Lock()
# Notify not_empty whenever an item is added to the queue; a
# thread waiting to get is notified then.
self.not_empty = _threading.Condition(self.mutex)
# Notify not_full whenever an item is removed from the queue;
# a thread waiting to put is notified then.
self.not_full = _threading.Condition(self.mutex)
# Notify all_tasks_done whenever the number of unfinished tasks
# drops to zero; thread waiting to join() is notified to resume
self.all_tasks_done = _threading.Condition(self.mutex)
self.unfinished_tasks = 0 def task_done(self):
"""Indicate that a formerly enqueued task is complete. Used by Queue consumer threads. For each get() used to fetch a task,
a subsequent call to task_done() tells the queue that the processing
on the task is complete. If a join() is currently blocking, it will resume when all items
have been processed (meaning that a task_done() call was received
for every item that had been put() into the queue). Raises a ValueError if called more times than there were items
placed in the queue.
"""
self.all_tasks_done.acquire()
try:
unfinished = self.unfinished_tasks - 1
if unfinished <= 0:
if unfinished < 0:
raise ValueError('task_done() called too many times')
self.all_tasks_done.notify_all()
self.unfinished_tasks = unfinished
finally:
self.all_tasks_done.release() def join(self):
"""Blocks until all items in the Queue have been gotten and processed. The count of unfinished tasks goes up whenever an item is added to the
queue. The count goes down whenever a consumer thread calls task_done()
to indicate the item was retrieved and all work on it is complete. When the count of unfinished tasks drops to zero, join() unblocks.
"""
self.all_tasks_done.acquire()
try:
while self.unfinished_tasks:
self.all_tasks_done.wait()
finally:
self.all_tasks_done.release() def qsize(self):
"""Return the approximate size of the queue (not reliable!)."""
self.mutex.acquire()
n = self._qsize()
self.mutex.release()
return n def empty(self):
"""Return True if the queue is empty, False otherwise (not reliable!)."""
self.mutex.acquire()
n = not self._qsize()
self.mutex.release()
return n def full(self):
"""Return True if the queue is full, False otherwise (not reliable!)."""
self.mutex.acquire()
n = 0 < self.maxsize == self._qsize()
self.mutex.release()
return n def put(self, item, block=True, timeout=None):
"""Put an item into the queue. If optional args 'block' is true and 'timeout' is None (the default),
block if necessary until a free slot is available. If 'timeout' is
a non-negative number, it blocks at most 'timeout' seconds and raises
the Full exception if no free slot was available within that time.
Otherwise ('block' is false), put an item on the queue if a free slot
is immediately available, else raise the Full exception ('timeout'
is ignored in that case).
"""
self.not_full.acquire()
try:
if self.maxsize > 0:
if not block:
if self._qsize() == self.maxsize:
raise Full
elif timeout is None:
while self._qsize() == self.maxsize:
self.not_full.wait()
elif timeout < 0:
raise ValueError("'timeout' must be a non-negative number")
else:
endtime = _time() + timeout
while self._qsize() == self.maxsize:
remaining = endtime - _time()
if remaining <= 0.0:
raise Full
self.not_full.wait(remaining)
self._put(item)
self.unfinished_tasks += 1
self.not_empty.notify()
finally:
self.not_full.release() def put_nowait(self, item):
"""Put an item into the queue without blocking. Only enqueue the item if a free slot is immediately available.
Otherwise raise the Full exception.
"""
return self.put(item, False) def get(self, block=True, timeout=None):
"""Remove and return an item from the queue. If optional args 'block' is true and 'timeout' is None (the default),
block if necessary until an item is available. If 'timeout' is
a non-negative number, it blocks at most 'timeout' seconds and raises
the Empty exception if no item was available within that time.
Otherwise ('block' is false), return an item if one is immediately
available, else raise the Empty exception ('timeout' is ignored
in that case).
"""
self.not_empty.acquire()
try:
if not block:
if not self._qsize():
raise Empty
elif timeout is None:
while not self._qsize():
self.not_empty.wait()
elif timeout < 0:
raise ValueError("'timeout' must be a non-negative number")
else:
endtime = _time() + timeout
while not self._qsize():
remaining = endtime - _time()
if remaining <= 0.0:
raise Empty
self.not_empty.wait(remaining)
item = self._get()
self.not_full.notify()
return item
finally:
self.not_empty.release() def get_nowait(self):
"""Remove and return an item from the queue without blocking. Only get an item if one is immediately available. Otherwise
raise the Empty exception.
"""
return self.get(False) # Override these methods to implement other queue organizations
# (e.g. stack or priority queue).
# These will only be called with appropriate locks held # Initialize the queue representation
def _init(self, maxsize):
self.queue = deque() def _qsize(self, len=len):
return len(self.queue) # Put a new item in the queue
def _put(self, item):
self.queue.append(item) # Get an item from the queue
def _get(self):
return self.queue.popleft()
Queue.Queue
队列：先进先出（fifo）
栈：像弹夹一样，子弹先进去后出来。
四.标准数据类型特性总结
按存值个数区分
| 标量／原子类型 | 数字，字符串 |
| 容器类型 | 列表，元组，字典 |
按可变不可变区分
| 可变 | 列表，字典 |
| 不可变 | 数字，字符串，元组 |
按访问顺序区分
| 直接访问 | 数字 |
| 顺序访问（序列类型） | 字符串，列表，元组 |
| key值访问（映射类型） |
字典 |
迭代器和生成器
一、迭代器
对于Python 列表的 for 循环，他的内部原理：查看下一个元素是否存在，如果存在，则取出，如果不存在，则报异常 StopIteration。（python内部对异常已处理）
class listiterator(object)
| Methods defined here:
|
| __getattribute__(...)
| x.__getattribute__('name') <==> x.name
|
| __iter__(...)
| x.__iter__() <==> iter(x)
|
| __length_hint__(...)
| Private method returning an estimate of len(list(it)).
|
| next(...)####必须要有这个方法，才能循环取值
| x.next() -> the next value, or raise StopIteration
二、生成器
类似于数据库中的线程池一样，我先不提供链接，等有访问过来，我在生产连接，也就是什么时候用我就什么时候产生。
生成器内部基于yield创建，即：对于生成器只有使用时才创建，从而不避免内存浪费
range不是生成器 和 xrange 是生成器
readlines不是生成器 和 xreadlines 是生成器
>>> print range(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> print xrange(10)
xrange(10)
通过range循环一个列表---下标式循环
li = [11,22,33,44,55,66]
for i in range(6):
print li[i]
........
......
11
22
33
44
55
66
下标循环 len(li)
练习：<br>有如下列表：
[13, 22, 6, 99, 11]
请按照一下规则计算：
13 和 22 比较，将大的值放在右侧，即：[13, 22, 6, 99, 11]
22 和 6 比较，将大的值放在右侧，即：[13, 6, 22, 99, 11]
22 和 99 比较，将大的值放在右侧，即：[13, 6, 22, 99, 11]
99 和 42 比较，将大的值放在右侧，即：[13, 6, 22, 11, 99,]
13 和 6 比较，将大的值放在右侧，即：[6, 13, 22, 11, 99,]
这其实就是一个冒泡算法
li = [13, 22, 6, 99, 11]
for m in range(len(li)-1):
for n in range(m+1, len(li)):
if li[m]> li[n]:
temp = li[n]
li[n] = li[m]
li[m] = temp
print li
深浅拷贝
为什么要拷贝？
当进行修改时，想要保留原来的数据和修改后的数据
数字字符串 和 集合 在修改时的差异？ （深浅拷贝不同的终极原因）
在修改数据时：
数字字符串：在内存中新建一份数据 集合：修改内存中的同一份数据对于集合，如何保留其修改前和修改后的数据？
在内存中拷贝一份
对于集合，如何拷贝其n层元素同时拷贝？
深拷贝
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