>>> a=[1,2,3]
>>> b=a
>>> c=a[:]
>>> a
[1, 2, 3]
>>> b
[1, 2, 3]
>>> c
[1, 2, 3]
>>> a[0]=88
>>> a
[88, 2, 3]
>>> b
[88, 2, 3]
>>> c
[1, 2, 3]
>>> a[1]="this is s s "
>>> a
[88, 'this is s s ', 3]
>>> b
[88, 'this is s s ', 3]
>>> c
[1, 2, 3]
>>> a+b
[88, 'this is s s ', 3, 88, 'this is s s ', 3]
>>> a*5
[88,
'this is s s ',
3,
88,
'this is s s ',
3,
88,
'this is s s ',
3,
88,
'this is s s ',
3,
88,
'this is s s ',
3]
>>> 1 in a
False
>>> "thsi" in a
False
>>>
>>> del a[2]
>>> a
[88, 'this is s s ']
复制的例如 c=a[:] 改变a 但是c不变；同指向一个list的a与b，改变list后，都会改变；
索引，改变，置换，复制，加和，乘法，是否在里面，删减，
