Python list | insert()
insert() is an inbuilt function in Python that inserts a given element at a given index in a list.
Syntax :
list_name.insert(index, element)
Parameters :
index - the index at which the element has to be inserted. element - the element to be inserted in the list.
Returns :
This method does not return any value but it inserts the given element at the given index.
Error :
If anything other then a list is used with insert(), then it returns an AttributeError.
Note : If given index >= length(list) is given, then it inserts at the end of the list.
Code #1 :
# Python3 program for use # of insert() method list1 = [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ] # insert 10 at 4th index list1.insert( 4 , 10 ) print (list1) list2 = [ 'a' , 'b' , 'c' , 'd' , 'e' ] # insert z at the front of the list list2.insert( 0 , 'z' ) print (list2) |
Output :
[1, 2, 3, 4, 10, 5, 6, 7] ['z', 'a', 'b', 'c', 'd', 'e']
Code #2 :
# Python3 program for error # of insert() method # attribute error string = "1234567" string.insert( 10 , 1 ) print (string) |
Output :
Traceback (most recent call last): File "/home/2fe54bd8723cd0ae89a17325da8b2eb5.py", line 7, in string.insert(10, 1) AttributeError: 'str' object has no attribute 'insert'
Practical Application :
Insertion in a list before any element :
Code #3 :
# Python3 program for Insertion in a list # before any element using insert() method list1 = [ 1 , 2 , 3 , 4 , 5 , 6 ] # Element to be inserted element = 13 # Element to be inserted before 3 beforeElement = 3 # Find index index = list1.index(beforeElement) # Insert element at beforeElement list1.insert(index, element) print (list1) |
Output :
[1, 2, 13, 3, 4, 5, 6]
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