列表应用2 (day 8)
names = ["Liuyang","yaopeng",["yp","yaop"]] #列表里可嵌套列表 用二维数组方式访问
names[2][0] = "yp"
print(names[0:2:1]]) #切片片长
输出:"Liuyang","yaopeng",["yp","yaop"] 起始值0,终止-1,步长1 均可以省略不写
for i in names:
print(i) 输出每一个字段
>>>
import
copy
>>>
list
=
[
1
,
2
, [
3
,
4
]]
>>> copy_list
=
copy.copy(
list
)
>>> deepcopy_list
=
copy.deepcopy(
list
)
>>>
>>>
id
(
list
)
44454296
>>>
id
(copy_list)
44515736
>>>
id
(deepcopy_list)
44455736
>>>
>>>
for
k
in
list
:
...
print
id
(k)
43338088
43338076
44430120
>>>
for
k
in
copy_list:
...
print
id
(k)
43338088
43338076
44430120
# copy对象的内容和原对象完全一样
>>>
for
k
in
deepcopy_list:
...
print
id
(k)
43338088
43338076
44457456
# deepcopy对象的内容和原对象有区别:列表元素的id不一样;数字元素id一样,原因是所有相同数字的变量的引用都是一样的。