自学python成长记录2：导入模块时需要注意的地方

在python中导入模块的方法有多种，对于刚开始学习的来说，有些细节容易忽视。

先创建一个包含函数make_pizza()的模块：pizza.py

def make_pizza(size,*toppings):
    """概述要制作的比萨"""
    print(f"nMaking a {size}-inch pizza with the following toppings:")
    for topping in toppings:
        print(f"-{topping}")

导入格式：import 模块名

调用格式：模块名.函数名(实参)

例如创建一个名为making_pizzas.py 的文件，导入刚创建的模块（pizza.py）

import pizza

pizza.make_pizza(16,'pepperoni')
pizza.make_pizza(12,'mushrooms','green peppers','extra cheese')

输出结果为： 

Making a 16-inch pizza with the following toppings:
-pepperoni

Making a 12-inch pizza with the following toppings:
-mushrooms
-green peppers
-extra cheese
[Finished in 214ms

如果调用函数不写模块名则会出现错误。

import pizza

make_pizza(16,'pepperoni')
make_pizza(12,'mushrooms','green peppers','extra cheese')

输出结果为：

NameError: name 'make_pizza' is not defined

导入格式：from 模块名 import 函数名

                   from 模块名 import 函数_1,函数_2,函数_3,....

调用格式：函数名(实参)

还是以making_pizzas.py为例

from pizza import make_pizza

make_pizza(16,'pepperoni')
make_pizza(12,'mushrooms','green peppers','extra cheese')

输出结果正确：

Making a 16-inch pizza with the following toppings:
-pepperoni

Making a 12-inch pizza with the following toppings:
-mushrooms
-green peppers
-extra cheese
[Finished in 185ms]

如果调用函数的时候写上了模块名，则会提示错误：

from pizza import make_pizza

pizza.make_pizza(16,'pepperoni')
pizza.make_pizza(12,'mushrooms','green peppers','extra cheese')

输出结果为：

NameError: name 'pizza' is not defined