Python 使用dict实现switch的操作

# -*- coding: utf-8 -*-
"""
Python利用dict实现switch
""" 
def add(x, y): return x + y  
def subtract(x, y): return x - y           
def multiply(x, y): return x * y 
def divide(x, y):
  assert(y != 0)      
  return x / y 
mapping = {"+": add, "-": subtract, "*": multiply, "/": divide}
 
def cal(x, y, symbol="+"):
  assert(symbol in mapping)
  return mapping.get(symbol)(x, y) 
if __name__ == "__main__":
  result = cal(3, 0, "&")

#!/usr/bin/python3 
# conf_cmd = conf_items["cmd"].split(":")[0] 
test_no = "T1"
#test_no = "T2"
#test_no = "T3"
 
id = 1 
def test1(id):
  print("test1:%d" % id)
 
def test2(id):
  print("test2")
 
def test3(id):
  print("test3")
 
funcs = {"T1": test1,
     "T2": test2,
     "T3": test3} 
try:
  func = funcs[test_no]
  func(id)
except Exception:
  pass

test1:1

def operator(o,x,y):
 result={
     '+' : x+y,
     '-' : x-y,
     '*' : x*y,
     '/' : x/y
  }
 print(result.get(o))
oper=input()//接收从键盘输入的数据
operator(oper,4,2)