The path to Python, sixth: Introduction to Python and Basics 6

Python list

Introduction to sequence types (sequence)

String str
Lists List
Ganso tuple

Concept:

Lists are made up of a series of specific elements that may not have any association between them, but they have a sequential relationship
Lists can change the values of individual elements
A list is a container.

Empty list: L = [] # empty list

L = List () # empty lists, is a function

Create a non-empty list:

L = [1,2,3,4,5]

List of generated functions lists ():

List () generates an empty list equal to [];

List (iterable) with an iterative object to initialize the lists

Example:

1>>> l=list (Range (11))2>>>L3[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]4>>>5>>> s='ABCDEFG'6>>> l=list (s)7>>>L8['a','b','C','D','e','F','g']9>>>

List1

List of operators

+, + =, *, *=

Description: The + operator is used for splicing lists, and the + = operator is used for the new list generated from the original list and the right-hand list (x = X+y equals x +=y)

The * operator is used to generate duplicate lists; * = operator is used to generate duplicate lists for the original list and to change the binding of variables;

1>>> x=[1,2,3]2>>> y=[4,5,6]3>>> z = x +y4>>>Z5[1, 2, 3, 4, 5, 6]6>>>Len (z)768>>> m = y +x9>>>mTen[4, 5, 6, 1, 2, 3]   One>>>Len (m) A6 ->>>

+ number Stitching

1 >>> x=[1,2,3]2 >>> y=[4,5,6]3 >>> x + = y  4 >>> x5 [1, 2, 3, 4, 5, 6]6 >>> y  7 [4, 5, 6]8

+ = number stitching

1 >>> [+] * 32 [1, 2, 1, 2, 1, 2]3 >>> 3 * [4] > [1, 2, 1, 2, 1, 2]5

*

1 >>> x = [x-ray]2 >>> *= 43 >>> x 4 [1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3]5

*=

Relational (comparison) operators for lists:

> >= < <= = = =!

1>>> x = [A]2>>> y = [2,3,4]3>>> x! =y4 True5>>> x >y6 False7>>> x <y8 True9>>> x = =yTen False One>>> [3,2,1] = = [] A False ->>> [1,' Both'] < [' Both', 1] - Traceback (most recent): theFile"<pyshell#59>", Line 1,inch<module> -[1,' Both'] < [' Both', 1] -Typeerror:unorderable Types:int () <str () ->>>#strings and lists are not comparable

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The path to Python, sixth: Introduction to Python and Basics 6