python-------------自定义str转换成int的函数

# -*- coding: utf-8 -*-
# Author	:Gogh
# @Time		:2017/12/7 15:39
# @Email	:[email protected]
def str2int(s):
    def fn(x, y):
        return x * 10 + y
    def char(s):
        return {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}[s]
    return reduce(fn, map(char, s))
print (str2int('545455'))
# lambda函数进一步简化
def char2num(s):
    return {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}[s]
def str2int(s):
    return reduce(lambda x, y: x*10+y, map(char2num, s))
print (str2int('1211212'))