在這道習(xí)題中，我們將關(guān)注函數(shù)的返回值。

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

def add(a, b):
    print(f"ADDING {a} + ")
    return a + b

def subtract(a, b):
    print(f"SUBTRACTING {a} - ")
    return a - b

def multiply(a, b):
    print(f"MULTIPLYING {a} * ")
    return a * b

def divide(a, b):
    print(f"DIVIDING {a} / ")
    return a / b

print("Let's do some math with just functions!")

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

print(f"Age: {age}, Height: {height}, Weight: {weight}, IQ: {iq}")


# A puzzle for the extra credit, type it in anyway.
print("Here is a puzzle.")

what = add(age, subtract(height, multiply(weight, divide(iq, 2))))

print("That becomes: ", what, "Can you do it by hand?")

運(yùn)行結(jié)果如下：

ex21運(yùn)行結(jié)果

ex21中的程序邏輯是：

1. 定義了四則運(yùn)算的4個(gè)函數(shù)。
2. 依次調(diào)用4個(gè)函數(shù)，計(jì)算出了age、height、weight和iq，并打印。
3. 最后以嵌套調(diào)用的方式計(jì)算了出了變量what的值，并打印。

在這里，我們重點(diǎn)需要關(guān)注函數(shù)中的返回值是如何得到的？答案就在于Python中return的這個(gè)關(guān)鍵字。將函數(shù)的返回值寫在return后面，函數(shù)就擁有了返回值。

小結(jié)

1. 定義函數(shù)的返回值。