python switch语句的实现方法

from __future__ import division

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) :
    return x / y

def calculate(x, y, symbol) :
    if   "+" == symbol :
        print add(x, y)
    elif "-" == symbol :
        print subtract(x, y)
    elif "*" == symbol :
        print multiply(x, y)
    elif "/" == symbol :
        print divide(x, y)
    else :
        pass

calculate(1, 2, "+")
calculate(1, 2, "-")
calculate(1, 2, "*")
calculate(1, 2, "/")

from __future__ import division

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) :
    return x / y

calculateDict = {"+":add, "-":subtract, "*":multiply, "/":divide}

#print calculateDict["+"](1,2)
#print calculateDict.get("+")(1,2)

def calculate(x, y, symbol) :
     print calculateDict.get(symbol)(x, y)

calculate(1, 2, "+")
calculate(1, 2, "-")
calculate(1, 2, "*")
calculate(1, 2, "/")

from __future__ import division

def calculate(x, y, symbol) :
    calculateDict = {
            "+" : x + y     ,
            "-"  : x - y      ,
            "*"  : x * y     ,
            "/"  : x / y    
            }
    print calculateDict.get(symbol)

calculate(1, 2, "+")   
calculate(1, 2, "-")   
calculate(1, 2, "*")   
calculate(1, 2, "/")