python switch高效替代_python 中无switch（写了几个函数代替switch）

字典的常用用途之一代替switch

在C/C++/Java语言中，有个很方便的函数switch，比如:

复制代码代码如下:

public class test {

public static void main(String[] args) {

String s = "C";

switch (s){

case "A":

System.out.println("A");

break;

case "B":

System.out.println("B");

break;

case "C":

System.out.println("C");

break;

default:

System.out.println("D");

}

}

}

在Python中要实现同样的功能，

方法一，就是用if, else语句来实现，比如:

from __future__ import division

def add(x, y):

return x + y

def sub(x, y):

return x - y

def mul(x, y):

return x * y

def div(x, y):

return x / y

def operator(x, y, sep=‘+‘):

if sep == ‘+‘: print add(x, y)

elif sep == ‘-‘: print sub(x, y)

elif sep == ‘*‘: print mul(x, y)

elif sep == ‘/‘: print div(x, y)

else: print ‘Something Wrong‘

print __name__

if __name__ == ‘__main__‘:

x = int(raw_input("Enter the 1st number: "))

y = int(raw_input("Enter the 2nd number: "))

s = raw_input("Enter operation here(+ - * /): ")

operator(x, y, s)

方法二，用字典来巧妙实现同样的switch的功能，比如:

复制代码代码如下:

#coding=gbk

from __future__ import division

x = int(raw_input("Enter the 1st number: "))

y = int(raw_input("Enter the 2nd number: "))

def operator(o):

dict_oper = {

‘+‘: lambda x, y: x + y,

‘-‘: lambda x, y: x - y,

‘*‘: lambda x, y: x * y,

‘/‘: lambda x, y: x / y}

return dict_oper.get(o)(x, y)

if __name__ == ‘__main__‘:

o = raw_input("Enter operation here(+ - * /): ")

print operator(o)

如果觉得《python switch高效替代_python 中无switch（写了几个函数代替switch）》对你有帮助，请点赞、收藏，并留下你的观点哦！