CS 61 A (Part 3)

>>> 2
2
>>> print(2)
2
>>> 'hello'
'hello'
>>> print('hello')
hello
>>>
>>> None
>>>
>>> print(None)
None
>>>

None 什么都不会输出

>>> x=print(1)
1
>>> x
>>>
>>> print(x)
None
>>>

print 返回的是none