Python-13 函数，Python的乐高积木

函数 

函数的创建和调用

>>> def MyFirstFunction():
	print('hello world')
	print('this is my first function')

	
>>> MyFirstFunction()
hello world
this is my first function
>>> 

如果调用没有定义的函数名

>>> MySecondFunction()
Traceback (most recent call last):
  File "<pyshell#5>", line 1, in <module>
    MySecondFunction()
NameError: name 'MySecondFunction' is not defined
>>> 

函数中增加参数

>>> def MySecondFunction(name):
	print('Hi '+name)

	
>>> MySecondFunction()
Traceback (most recent call last):
  File "<pyshell#9>", line 1, in <module>
    MySecondFunction()
TypeError: MySecondFunction() missing 1 required positional argument: 'name'
>>> MySecondFunction('Ethan')
Hi Ethan
>>> 

函数增加return

>>> def MyThirdFunction(num1,num2):
	result = num1 + num2
	return result

>>> MyThirdFunction()
Traceback (most recent call last):
  File "<pyshell#15>", line 1, in <module>
    MyThirdFunction()
TypeError: MyThirdFunction() missing 2 required positional arguments: 'num1' and 'num2'
>>> MyThirdFunction(3,5)
8
>>> 

>>> print(MyThirdFunction(3,5))
8
>>> 

python的参数可以有多个，但不建议过多，不便于维护。

函数，对象，模块