#在16进制中的位置

num = "b"

v = int(num, base=16)

print(v)    #11

# 1  1

# 2  10

# 3  11

# 4  100

# 5  101

# 当前数字的二进制，至少用n位表示

age = 5

r = age.bit_length()

print(r)   #

age = 2

r = age.bit_length()

print(r)   #

test = "alexalex"

v = test.find('lex',3)

print(v)

从第3个位置'x'查找'lex'

test = 'i am {name}, age {a}'

print(test)

v = test.format(name='alex',a=19)

print(v)

test = 'i am {0}, age {1}'

print(test)

v = test.format('alex',19)

print(v)

#格式化，传入的值 {"name": 'alex', "a": 19}

test = 'i am {name}, age {a}'

v1 = test.format(name='df',a=10)

v2 = test.format_map({"name": 'alex', "a": 19})

print(v1)

print(v2)

test = "aLEx"

#首字母大写

v = test.capitalize()

print(v)

#所有字母大写

v2 = test.upper()

print(v2)

# 所有变小写，casefold更牛逼，很多未知的对相应变小写

v3 = test.casefold()

print(v3)

v4 = test.lower()

print(v4)

#设置宽度，并将内容居中

# 20 代指总长度

# *  空白未知填充，一个字符，可有可无

test = 'alex'

v = test.center(20,"中")

print(v)      # 中中中中中中中中alex中中中中中中中中

# 去字符串中寻找，寻找子序列的出现次数

test = "aLexalexr"

v = test.count('ex')

print(v)   #

test = "aLexalexr"

v = test.count('ex',5,7)

print(v)   #

v = test.count('ex',5,8)

print(v)   #

# 以什么什么结尾

# 以什么什么开始

test = "alex"

v1 = test.endswith('ex')

print(v1)    # False

v2 = test.startswith('ex')

print(v2)    # True

# 字符串中是否只包含 字母、数字或汉字

test = "123d好"

v1 = test.isalnum()

print(v1)   # True

# 字符串中是否只包含 字母或汉字

v2 = test.isalpha()

print(v2)   # False

# test = "二" # 1，② ， 是否为数字

test = ''

v1 = test.isdecimal()

v2 = test.isdigit()    #包含②

v3 = test.isnumeric()  #包含“二”

print(v1,v2,v3)    #True True True

# 是否存在不可显示的字符

# \t   制表符

# \n   换行

test = "oiuas\tdfkj"

v = test.isprintable()

print(v)      # False

# 15 判断是否全部是空格

test = "    "

v = test.isspace()

print(v)     # True

# 16 判断是否是标题

test = "Return True if all cased characters in S"

v1 = test.istitle()

print(v1)     # False

v2 = test.title()

print(v2)     # Return True If All Cased Characters In S

v3 = v2.istitle()

print(v3)     # True

# 17 ***** 将字符串中的每一个元素按照指定分隔符进行拼接

test = "你是风儿我是沙"

print(test)

t = ' '

v = t.join(test)

print(v)     # 你 是 风 儿 我 是 沙

# 18 判断是否全部是大小写 和 转换为大小写

test = "Alex"

v1 = test.islower()

v2 = test.lower()

print(v1, v2)     # False alex

v1 = test.isupper()

v2 = test.upper()

print(v1,v2)      # False ALEX

# 移除指定字符串

test = "wxadx"

v1 = test.lstrip('x')

v2 = test.rstrip('x')

v3 = test.strip('x')

print(v1,v2,v3)    # wxadx wxad wxad

# 去除左右空白

v = '  df  '

print(v)     # '  df  '

v1 = v.lstrip()

v2 = v.rstrip()

v3 = v.strip()

print(v1)    # 'df  '

print(v2)    # '  df'

print(v3)    # 'df'

# 对应关系替换

test =  "aeiou"

test1 = ""

v = "asidufkasd;fiuadkf;adfkjalsdjf"

m = str.maketrans("aeiou", "")

new_v = v.translate(m)

print(new_v)     # 1s3d5fk1sd;f351dkf;1dfkj1lsdjf

# 21 分割为三部分

test = "testasdsddfg"

v = test.partition('s')

print(v)     # ('te', 's', 'tasdsddfg')

v = test.rpartition('s')

print(v)     # ('testasd', 's', 'ddfg')

# 分割为指定个数

test = "testasdsddfg"

v1 = test.split('s',2)

print(v1)     # ['te', 'ta', 'dsddfg']

v2 = test.rsplit('s',2)

print(v2)     # ['testa', 'd', 'ddfg']

# 分割，只能根据，true，false：是否保留换行

test = "asdfadfasdf\nasdfasdf\nadfasdf"

v1 = test.splitlines(True)

print(v1)     # ['asdfadfasdf\n', 'asdfasdf\n', 'adfasdf']

v2 = test.splitlines(False)

print(v2)     # ['asdfadfasdf', 'asdfasdf', 'adfasdf']

# 大小写转换

test = "aLex"

v = test.swapcase()

print(v)     # AlEX

# 将指定字符串替换为指定字符串

test = "alexalexalex"

v = test.replace("ex",'bbb')

print(v)     #全部替换

v = test.replace("ex",'bbb',2)

print(v)     #替换前两个

test = "郑建文妹子有种冲我来"

for item in test:

    print(item)     

郑
建
文
妹
子
有
种
冲
我
来

# 二、索引，下标，获取字符串中的某一个字符

test = '123dg'

v = test[3]

print(v)     # d

# 三、切片

test = '12df56'

v = test[0:2]

print(v)     # 12d

# 四、获取长度

# Python3： len获取当前字符串中由几个字符组成

test = 'asdfg'

v = len(test)

print(v)     #