The best Python3 list Tutorial In 2024, In this tutorial you can learn Access list value,update list,Remove list element,Python script list operator,Python list interception and splicing,Nested list,Python list of functions & methods,
Python sequence is the most basic data structure. Each element in the sequence is assigned a number - its position, or index, the first index is 0, the second index is 1, and so on.
Python has a built-in types 6 sequence, but the most common are lists and tuples.
Sequence of operations can be carried out, including indexing, slicing, add, multiply, check the members.
Moreover, Python has a built-determine the length of the sequence and determining the maximum and minimum element method.
Python is a list of the most commonly used type of data, it can be used as a comma-separated values appear in square brackets.
List of data items need not have the same type
Create a list as long as the comma-delimited data items using different brackets can be. As follows:
list1 = ['Google', 'w3big', 1997, 2000]; list2 = [1, 2, 3, 4, 5 ]; list3 = ["a", "b", "c", "d"];
With the index of the string as a list of index starts from 0. List can be intercepted, combinations and the like.
Use subscripting to access values in the list, you can also use square brackets in the form of interception of character, as follows:
#!/usr/bin/python3 list1 = ['Google', 'w3big', 1997, 2000]; list2 = [1, 2, 3, 4, 5, 6, 7 ]; print ("list1[0]: ", list1[0]) print ("list2[1:5]: ", list2[1:5])
Examples of the above output:
list1[0]: Google list2[1:5]: [2, 3, 4, 5]
#!/usr/bin/python3 list = ['Google', 'w3big', 1997, 2000] print ("第三个元素为 : ", list[2]) list[2] = 2001 print ("更新后的第三个元素为 : ", list[2])
We will discuss the use of the next chapter in the append () method: Note
Examples of the above output:
第三个元素为 : 1997 更新后的第三个元素为 : 2001
You can use the del statement to remove elements of the list, the following examples:
#!/usr/bin/python3 list = ['Google', 'w3big', 1997, 2000] print (list) del list[2] print ("删除第三个元素 : ", list)
Examples of the above output:
删除第三个元素 : ['Google', 'w3big', 2000]
We will discuss the use of the next chapter in the remove () method: Note
List of + and * operators and string similarity. + Sign for the combined list, an asterisk for the repeat list.
As follows:
Python expression | result | description |
---|---|---|
len ([1, 2, 3]) | 3 | length |
[1, 2, 3] + [4, 5, 6] | [1, 2, 3, 4, 5, 6] | combination |
[ 'Hi!'] * 4 | [ 'Hi!', 'Hi!', 'Hi!', 'Hi!'] | repeat |
3 in [1, 2, 3] | True | Whether the elements are present in the list |
for x in [1, 2, 3]: print x, | 123 | Iteration |
Python list interception string type of operation, as follows:
L=['Google', 'w3big', 'Taobao']
operating:
Python expression | result | description |
---|---|---|
L [2] | 'Taobao' | Read the third element |
L [-2] | 'W3big' | The second element of the countdown start reading from the right: count from the right |
L [1:] | [ 'W3big', 'Taobao'] | Output all elements from the start of the second element |
>>> L=['Google', 'w3big', 'Taobao'] >>> L[2] 'Taobao' >>> L[-2] 'w3big' >>> L[1:] ['w3big', 'Taobao'] >>>
The list also supports the splicing operation:
>>> squares = [1, 4, 9, 16, 25] >>> squares + [36, 49, 64, 81, 100] [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
Nested list is created using the other lists in the list, for example:
>>> a = ['a', 'b', 'c'] >>> n = [1, 2, 3] >>> x = [a, n] >>> x [['a', 'b', 'c'], [1, 2, 3]] >>> x[0] ['a', 'b', 'c'] >>> x[0][1] 'b'
Python includes the following functions:
No. | function |
---|---|
1 | len (list) The number of list elements |
2 | max (list) Back to the list of elements Max |
3 | min (list) Returns a list of the minimum elements |
4 | list (seq) Will be converted to a list of tuples |
Python includes the following methods:
No. | method |
---|---|
1 | list.append (obj) In the end of the list to add new objects |
2 | list.count (obj) Number of times an element statistics appear in the list |
3 | list.extend (seq) Multiple values at the end of the list of additional disposable another sequence (extension of the original list with a new list) |
4 | list.index (obj) Find the index position of the first occurrence of a value from a list |
5 | list.insert (index, obj) Insert objects into a list |
6 | list.pop (obj = list [-1] ) Remove one element in the list (by default the last element), and returns the value of the element |
7 | list.remove (obj) Remove the list a value of the first match |
8 | list.reverse () Reverse list element |
9 | list.sort ([func]) The original list is sorted |
10 | list.clear () Clear List |
11 | list.copy () Copy List |