Python列表详解（二）

来源：互联网发布：python list函数编辑：程序博客网时间：2024/05/15 11:19

交互解释器

Python 2.7.11 (v2.7.11:6d1b6a68f775, Dec  5 2015, 20:40:30) [MSC v.1500 64 bit (AMD64)] on win32Type "help", "copyright", "credits" or "license" for more information.

关于列表的操作

定义列表

>>> world = ['a','b','c',['qwer','asdf'],1,2,3,'ChangerLee']

下标正取值

>>> world[1]'b'>>> world[3]['qwer', 'asdf']

下标反取值

>>> world[-2]3

元素全选操作符

>>> world[:]['a', 'b', 'c', ['qwer', 'asdf'], 1, 2, 3, 'ChangerLee']

元素片段操作

>>> world[2:]['c', ['qwer', 'asdf'], 1, 2, 3, 'ChangerLee']>>> world[:3]['a', 'b', 'c']>>> world[1:3]['b', 'c']>>>

列表的长度

>>> world['a', 'b', 'c', ['qwer', 'asdf'], 1, 2, 3, 'ChangerLee']>>> len(world)8

id方法：查看python中对象内存序列的内建方法

>>> help(id)Help on built-in function id in module __builtin__:id(...)    id(object) -> integer    Return the identity of an object.  This is guaranteed to be unique among    simultaneously existing objects.  (Hint: it's the object's memory address.)

列表的复制

>>> world['a', 'b', 'c', ['qwer', 'asdf'], 1, 2, 3, 'ChangerLee']>>> anotherworld=world[:]>>> id(world)50136648L>>> id(anotherworld)50137992L

列表取别名

>>> world['a', 'b', 'c', ['qwer', 'asdf'], 1, 2, 3, 'ChangerLee']>>> sameworld=world>>> id(world)50136648L>>> id(sameworld)50136648L>>>

列表的连接

>>> world['a', 'b', 'c', ['qwer', 'asdf'], 1, 2, 3, 'ChangerLee']>>> anotherworld+world['a', 'b', 'c', ['qwer', 'asdf'], 1, 2, 3, 'ChangerLee', 'a', 'b', 'c', ['qwer', 'asdf'], 1, 2, 3, 'ChangerLee']>>> [1,2,3]+[4,5,6][1, 2, 3, 4, 5, 6]>>> list1[5, 2, 3]>>> list1*3[5, 2, 3, 5, 2, 3, 5, 2, 3]>>> list1[5, 2, 3]

列表的逻辑操作
注意：列表的逻辑比较是列表的第一个元素的比较

>>> list1 = [1,2,3]>>> list2 = [4,5,6]>>> list1 < list2True>>> list1[0]=5>>> list1[5, 2, 3]>>> list1 < list2False

列表存在性判断not in 和in

>>> list2[4, 5, 6]>>> 5 in list2True>>> 3 not in list2True

列表中的列表元素存在性判断

>>> list1 = [1,2,3,['a','b','c']]>>> list1[3]['a', 'b', 'c']>>> 'a' in list1False>>> 'a' in list1[3]True>>> list1[3][2]'c'>>>

0 0