num1 = 10

num2 = 10.6

num3 = True

num4 = 3 + 4j

res = int(num1)      #10

res = int(num2)      #10

res = int(num3)      #1     False =>0

res = int(num4)      #error

res = float(num1)     #10.0

res = float(num2)     #10.6

res = float(num3)     #1.0     False =>0.0

res = float(num4)     #error

res = complex(num1)    #10 + 0j

res = complex(num2)    #10.6 + 0j

res = complex(num3)    #1 + 0j     False =>0j

res = complex(num4)    #3 + 4j

False:0,0.0,0j,False,"",[],(),set(),{},None

res = int()           #默认创建该数据类型的默认值

strvar = '我爱中国'

listvar = [0,'name',]

tuplevar = (0.0,'我爱python',[1,5+3j,],)

setvar = {0,1,2,3,4,5,5,}

dictvar = {"name":"bajie","age":18,}

res = str(listvar)

#将原类型最外层加"listvar"

print(res1,tpye(res1))

#repr 原型化输出字符串

prinr(repr(res1))

'''

str:将每一个字符单独作为一个元素放到列表

dice:将字典的键作为一个元素放到列表

其他容器:替换例如(1,) -> [1,]

'''

'''

str:将每一个字符单独作为一个元素放到元组

dice:将字典的键作为一个元素放到元组

其他容器:替换例如[1,] -> (1,)

'''

'''

str:将每一个字符单独作为一个元素放到集合

dice:将字典的键作为一个元素放到集合

其他容器:替换例如[1,2,] -> {2,1,}

'''

# 二级容器

listvar = [1,[2,]]

setvar = {'name',(1,2,)}

dictvar = {True:"中国"，{"nums":[1,2,3,4,5,6],}}

# 四级容器

lisvar = [1,[2,3,["name",[True,]]]]

# 等长(内容器不推荐集合，键值不确定)and TWO元素

datalist = [[1,2],["name","bajie"]]

dataset = {(1,2),{"name","bajie"}}

​

res = dict(datalist)          # {1: 2, 'name': 'bajie'}

res = dict(dataset)           # {1: 2, 'bajie':'name'}

​

# 奇葩写法

datastr = [[a,1],"b2"]        # {'a': 1, 'b': '2'}

'''

精度从低到高进行转换 ：bool - int - float - complex

'''

res1 = True + 1              # 2

res2 = True + 2j             # 1 + 2j

res3 = 1 + (2 + 2j)          # 1 + 2j

res4 = 0.2 + 2j              # 0.2 + 2j

res5 = False + 1 + 2.5 + 2j  # 3.5 + 2j

(同一文件，模块)

#1  整型 (-5 ~ 正无穷 <小数据池：id地址相同>)

#2  浮点型(非负数)

#3  bool值相同

#4  复数类型(只有虚数部分)

(不同文件，模块)

#1  整型 (-5 ~ 256 <小数据池：id地址相同>)

#1  strvar = "相同字符串"

#2  空元组