①类型转换函数
>>> a='520'
>>> b = int(a)
>>> b
转换浮点型数据会截断
>>> a= 520.520
>>> b= int(a)
>>> b
520
②float转换,将任何数字或者字符串(数字)转换为浮点型数据
>>> a = '520'
>>> b = float(a)
>>> b
520.0
>>> b = float(a)
>>> b
520.0
③str 将数据或者其他类型转换为字符串
>>> a=5.99
>>> b=str(a)
>>> b
'5.99'
>>> b=str(a)
>>> b
'5.99'
④获得数据类型的函数type()
>>> type('520')
<class 'str'>
>>> type(520)
<class 'int'>
>>> type(5.20)
<class 'float'>
⑤验证数据类型isinstance
>>> a='a'
>>> isinstance(a,str)
True