Python Learning-list Operations

Python list operation:

1. The sequence is the most basic data structure in Python. 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.
2. Python has 6 built-in types of sequences, but the most common are lists and tuples.
3. Sequences can be performed by operations including indexing, slicing, adding, multiplying, and checking members.
4. In addition, Python has built-in methods for determining the length of a sequence and determining the maximum and minimum elements.
5. A list is the most commonly used Python data type and can appear as a comma-separated value within a square bracket.
6. Data items for a list do not need to have the same type

List creation and update:

1 #List Updates2List = ['Physics','Chemistry', 1997,2000]3 Print('Value available at index 2:', List[2])#the index of the list starts at 0, followed by 14LIST[2] = 2001#the list can be updated by direct assignment5 Print('Value available at index 2:', list[2])6 7 #Results:8 #Value available at index 2:19979 #Value available at index 2:2001

Add elements to the list:

1 #adding elements to a list using append2List = ['Physics','Chemistry']3List.append ('Wangtao')#add element ' Wangtao ' to the list4 Print(list[1])5 Print(list)6 7 #Results8 #Chemistry9 #[' Physics ', ' chemistry ', ' Wangtao ']

To delete a list element:

1 #To delete a list element2List = ['Physics','Chemistry', 1997, 2000]3 Print(list)4 delLIST[1]#use the Del statement to delete a list element5 Print(list)6 7 #Results8 #[' Physics ', ' Chemistry ', 1997, +]9 #[' Physics ', 1997, +]

List operators:

1 #List Operators2 Importoperator3List = [1,2,3,4,5]4List2 = [2,3,4,5]5 Print(Len (list))#Len is used to get the length of the list6 Print(LIST+LIST2)#' + ' combines two elements of a list into a single list7 Print(list*2)#' * ' repeating list8 Print(3inchList#determines whether an element is in the list9 Print(6inchList#determines whether an element is in the listTen Print(max (list))#returns the maximum value of an element in a list One Print(min (list))#returns the minimum value of an element in a list A Print(Operator.eq (LIST,LIST2))

1 #some operator operations in Python2 operator.lt (A, b)3 Operator.le (A, b)4 Operator.eq (A, b)5 Operator.ne (A, b)6 operator.ge (A, b)7 operator.gt (A, b)8operator.__lt__(A, b)9operator.__le__(A, b)Tenoperator.__eq__(A, b) Oneoperator.__ne__(A, b) Aoperator.__ge__(A, b) -operator.__gt__(A, B)

 - #There is no CMP function in Python 3, you need to call the operator module if you need to compare the elements of the two list -  the  - #Results: - #5 - #[1, 2, 3, 4, 5, 2, 3, 4, 5] + #[1, 2, 3, 4, 5, 1, 2, 3, 4, 5] - #True + #False A #5 at #1 - #True

List interception:

1 #List Interception2List = ['Physics','Chemistry', 1997, 2000]3 Print(List[2])#an element with an output index of ' 2 '4 Print(List[-3])#The third element to the bottom of the output5 Print(list[1:])#output list elements starting from index ' 1 '6 7 #Results:8 #19979 #ChemistryTen #[' Chemistry ', 1997, +]

Remaining list operations:

1. List.append (obj): Add new Object 2, List.count (obj) at the end of the list: count the number of occurrences of an element in the list 3, list.extend (seq) : Append multiple values from another sequence at the end of the list (with a new list) 4, List.index (obj): Find a value from the list index position of the first occurrence 5, List.insert (index, obj): Inserts an object into List 6, List.pop (Obj=list[-1]): Removes an element from the list (the last element by default) and returns the value of the element 7, List.remove (obj): Removes the first occurrence of a value in the list 8, List.reverse () : Reverse list of elements 9, List.sort ([func]): Sort the original list

Python Learning-list Operations