函數可以返回某些東西。習題21---learn python the hard way.

#coding=utf-8

def plus(a, b):
    return a + b
 
def jian(a, b):
    return a - b
 
def cheng(a, b):
    return a * b
 
def chu(a, b):
    return a / b
 
x = plus(50, 10)
y = jian(50, 10)
z = cheng(50, 10)
z2 = chu(50, 20)

print " There're %d people who didn\'t pay, %d people who already paid, %d people promise will pay, %d peole will not pay." % (x, y, z, z2)

#可以這樣理解，假設我們把return全部換成print，這個代碼是不會運作的，因爲print不會返回 兩個參數之間的結果。

def worker(a, b, c):
    x = a + b
    y = x * c
    return y
 
result = worker(1, 2, 3)

print"result %d" % result