Python list remove()
Python List remove() is an inbuilt function in the Python programming language that removes a given object from the List.
Syntax:
list_name.remove(obj)Parameters:
- obj: object to be removed from the list
Returns:
The method does not return any value but removes the given object from the list.
Exception:
If the element doesn’t exist, it throws ValueError: list.remove(x): x not in list exception.
Note:
It removes the first occurrence of the object from the list.
Example 1: Remove element from the list
Python3
# Python3 program to demonstrate the use of # remove() method # the first occurrence of 1 is removed from the list list1 = [ 1 , 2 , 1 , 1 , 4 , 5 ] list1.remove( 1 ) print (list1) # removes 'a' from list2 list2 = [ 'a' , 'b' , 'c' , 'd' ] list2.remove( 'a' ) print (list2) |
Output
[2, 1, 1, 4, 5] ['b', 'c', 'd']
Example 2: Deleting element that doesn’t exist
Python3
# Python3 program for the error in # remove() method # removes 'e' from list2 list2 = [ 'a' , 'b' , 'c' , 'd' ] list2.remove( 'e' ) print (list2) |
Output:
Traceback (most recent call last): File "/home/e35b642d8d5c06d24e9b31c7e7b9a7fa.py", line 8, in list2.remove('e') ValueError: list.remove(x): x not in list
Example 3: Using remove() Method On a List having Duplicate Elements
Python3
# My List list2 = [ 'a' , 'b' , 'c' , 'd' , 'd' , 'e' , 'd' ] # removing 'd' list2.remove( 'd' ) print (list2) |
Output
['a', 'b', 'c', 'd', 'e', 'd']
Note: If a list contains duplicate elements, it removes the first occurrence of the object from the list.
Example 4: Given a list, remove all the 1’s from the list and print the list
Python3
# Python3 program for practical application # of removing 1 until all 1 are removed from the list list1 = [ 1 , 2 , 3 , 4 , 1 , 1 , 1 , 4 , 5 ] # looping till all 1's are removed while (list1.count( 1 )): list1.remove( 1 ) print (list1) |
Output
[2, 3, 4, 4, 5]
Example 5: Given a list, remove all the 2’s from the list using in keyword
Python3
# Python3 program for practical application # of removing 2 until all 2 are removed from the list mylist = [ 1 , 2 , 3 , 2 , 2 ] # looping till all 2's are removed while 2 in mylist: mylist.remove( 2 ) print (mylist) |
Output
[1, 3]
Complexity Class:
- Average case : O(N)
- Amortised Worst case : O(N)