Python数据类型转换汇总

# coding:utf-8: if __name__ == '__main__':    a = 1.56     print(int(a))  # 1     b = 1     print(float(b))  # 1.0

# coding:utf-8: if __name__ == '__main__':     a = '123'     print(int(a))  # 123     # print(int('123.0')) Error     # print(int('a123')) Error     b = 123     print(type(str(b)))  # 

 # coding:utf-8: if __name__ == '__main__':         a = 123.0     print(type(str(a)))  #      a = '123.01'     print(float(a))  # 123.01     # print(float('123.01.1')) Error     print(float('.123'))  # 0.123     print(float('123.'))  # 123.0     print(float('123'))  # 123.0

# coding:utf-8: if __name__ == '__main__':     '''     例1:list(string)能将字符串一个字符一个字符的切割为列表         string.join(list)能将list每一个元素之间以string相拼接形成字符串     例2:string.split(sep=None,max_split = -1) 按照指定字符和切割次数将字符串变成list         sep:切割符，默认切空格         max_split:切割次数 默认-1代表无限制，切完为止     '''     # 例1     print(list('abc'))  # ['a', 'b', 'c']     print(''.join(['a', 'b', 'c']))  # 'abc'     print(','.join(['a', 'b', 'c']))  # 'a,b,c'     # 例2     print('a,b,c'.split(',', 1))  # ['a', 'b,c']     print('a,b,c'.split(','))  # ['a', 'b', 'c']     print('a b c'.split())  # ['a', 'b', 'c']

# coding:utf-8: if __name__ == '__main__':     '''     例1:string转tuple使用tuple(string):得到的tuple由字符串的每一个字符构成         tuple不能直接转成string:可以先转list，后转string     '''     # 例1     string = '12344'     t = tuple(string)     print(t)  # ('1', '2', '3', '4', '4')     print(''.join(list(t)))  # '12344'

# coding:utf-8: if __name__ == '__main__':     '''     例1:list转tuple使用tuple(list)         tuple转list使用list(tuple)     '''     # 例1     a = ['a', 'b', 'c']     t = tuple(a)     print(t)  # ['a', 'b', 'c']     l = list(t)     print(l)  # ['a', 'b', 'c']

# coding:utf-8: if __name__ == '__main__':     '''     例1:None,0,空字符串，空list,空tuple,空dict，空set都能转成False，其它都能转成True     '''     # 例1     a = 1     print(bool(a))  # True     print(bool(2))  # True     print(bool(0))  # False     print(bool(None))  # False     print(bool([]))  # False     print(bool([1]))  # True     print(bool(set()))  # False     print(bool(set('1')))  # True     print(bool({}))  # False     print(bool({'name': 'xie'}))  # True     print(bool(''))  # False     print(bool(' '))  # True     print(bool('0'))  # True     print(bool('False'))  # True

# coding:utf-8: if __name__ == '__main__':     '''     例1:bool转int:True=>1,False=>0     例2:bool转float:True=>1.0,False=>0.0     例3:bool转string:True=>'True',False=>'False'     '''     a = True     b = False     # 例1     print(int(a))  # 1     print(int(b))  # 0     # 例2     print(float(a))  # 1.0     print(float(b))  # 0.0     # 例3     print(str(a))  # 'True'     print(str(b))  # 'False'