如何保存函数python,c语言保存函数

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python 字典可以储存函数吗

Python中是没有switch的, 所以有时我们需要用switch的用法, 就只能通过if else来实现了. 但if else写起来比较冗长,

这时就可以使用Python中的dict来实现, 比switch还要简洁. 用法如下:

如果是key1的情况就执行func1, 如果是key2的情况就执行func2...(func1, func2...所有的函数的参数形式需要相同),

假设各个函数参数均为(arg1, arg2):

dictName = {"key1":func1, "key2":func2, "key3":func3"...}#字典的值直接是函数的名字,不能加引号dictName[key](arg1, arg2)

示例代码如下:

#!/usr/bin/python#File: switchDict.py#Author: lxw#Time: 2014/10/05import redef add(x, y): return x + ydef sub(x, y): return x - ydef mul(x, y): return x * ydef div(x, y): return x / ydef main():

inStr = raw_input("Please input the easy expression:(e.g. 1 + 2.But 1 + 2 + 3 are not accepted.\n")

inList = re.split("(\W+)", inStr)

inList[1] = inList[1].strip() print("-------------------------") print(inList) print("-------------------------") #Method 1:

if inList[1] == "+": print(add(int(inList[0]), int(inList[2]))) elif inList[1] == "-": print(sub(int(inList[0]), int(inList[2]))) elif inList[1] == "*": print(mul(int(inList[0]), int(inList[2]))) elif inList[1] == "/": print(div(int(inList[0]), int(inList[2]))) else: pass

#Method 2:

try:

operator = {"+":add, "-":sub, "*":mul, "/":div} print(operator[inList[1]](int(inList[0]), int(inList[2]))) except KeyError: passif __name__ == '__main__':

main()

Output:

PS J:\ python .\switchDict.py

Please input the easy expression:(e.g. 1 + 2.But 1 + 2 + 3 are not accepted.1 + 2

-------------------------['1', '+', '2']-------------------------

3PS J:\ python .\switchDict.py

Please input the easy expression:(e.g. 1 + 2.But 1 + 2 + 3 are not accepted.4 - 9

-------------------------['4', '-', '9']-------------------------

-5

-5PS J:\ python .\switchDict.py

Please input the easy expression:(e.g. 1 + 2.But 1 + 2 + 3 are not accepted.6 / 5

-------------------------['6', '/', '5']-------------------------