笨办法21函数的返回值

代码如下：把第3行的加号换成了减号

def add(a, b):
    print "ADDING %d + %d" % (a, b)
    return a - b
def substract(a, b):
    print "SUBTRACTING %d - %d" % (a, b)
    return a - b
def multiply(a, b):
    print "MULTIPLYING %d * %d" % (a, b)
    return a * b
def divide(a, b):
    print "DIVIDING %d / %d" % (a, b)
    return a / b

age = add(30, 5)
height = substract(78, 4)
weight = multiply(90, 2)
iq = divide(100, 2)

print "Age: %d, Height: %d, Weight: %d, IQ:%d" % (age, height, weight, iq)

what = add(age, substract(height, multiply(weight, divide(iq, 2))))
print "That becomes:", what, "Can you do it by hand?"

运行结果可见，return的值和定义变量里print那一行的内容无关

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总觉得冗余的内容太多反而不利于理解，以下简化代码：

def add(a, b):
    return a - b
def substract(a, b):
    return a - b
def multiply(a, b):
    return a * b
def divide(a, b):
    return a / b

age = add(30, 5)
height = substract(78, 4)
weight = multiply(90, 2)
iq = divide(100, 2)

print "Age: %d, Height: %d, Weight: %d, IQ:%d" % (age, height, weight, iq)

what = add(age, substract(height, multiply(weight, divide(iq, 2))))
print "That becomes:", what, "Can you do it by hand?"

输出结果：