Python之str型轉成int型

str轉int:

def fn(x,y):
    return x*10+y

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]  # 特別注意這里，后面還有個 [s]

print(type(reduce(fn, map(char2num, '1738785'))))
print(reduce(fn, map(char2num, '1738785')))

輸出如下：

<type 'int'>
1738785

整理成一個 str2int 函數就是如下嘍：

from functools import reduce

def str2int(s):
    def fn(x,y):
        return x*10+y
    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]
    return reduce(fn,map(char2num,s))

print(str2int('365779'))
print(type(str2int('365779')))

 

用匿名函數lambda再簡化一下就成了下面這個樣子：

def str2int(s):
    return reduce(lambda x,y:x*10+y, map(lambda s:{'0':0, '1':1, '2':2, '3':3, '4':4, '5':5, '6':6, '7':7, '8':8, '9':9}[s], s))

WOC，就一行代碼哦，夠簡單！