In this article we will discuss different ways to remove an elements from list.

Remove an element from List by value using list.remove()

Python’s list provides a member function to remove an element from list i.e.

list.remove(value)

It removes the first occurrence of given element from the list.

For example,

Suppose we have a list of numbers i.e.

# List of numbers
listOfnum = [12, 44, 56, 45, 34, 3, 56, 4, 33, 44, 56]

Let’s remove 56 from the given list using list.remove() i.e.
# Remove first occurrence of 56 from List 
listOfnum.remove(56)

It will remove the first occurrence of 56 from the above lists. Lists contents will be now,
[12, 44, 45, 34, 3, 56, 4, 33, 44, 56]

If we try to remove the element that doesn’t exists in list then list.remove() will throw exception.
Therefore before calling list.remove() we should either,

Check if element exists in list i.e.

# Check if element exist in List, before removing
if 99 in listOfnum:
    listOfnum.remove(99)
else:
    print("Given Element Not Found in List")

Or use try / except i.e.
# If given element doesn't exists in list, then remove() can throw Error
# Therefore use try / except while calling list.remove()
try :
    listOfnum.remove(99)
except ValueError:
    print("Given Element Not Found in List")

Remove an element from List by Index using list.pop()

list.pop(index)

In python list’s pop() function will remove the element at given index and also returns the deleted element.
If index is not given then it deletes the last element.

For examples,

We have a list of ints i.e.

# List of numbers
listOfnum = [12, 44, 12, 56, 45, 34, 3, 56, 4, 33, 44, 56]

Let’s remove element at index 2
# Remove the element at index 2 in list    
value = listOfnum.pop(2)

List’s contents will be now
[12, 44, 56, 45, 34, 3, 56, 4, 33, 44, 56]

Returned value is 12 i.e. the deleted element.

list.pop() and Runtime Error

If list.pop() is called an index that is out of the boundary of List then it will generate a runtime error.
Therefore we should always check the size of list before calling list.pop() i.e.

# pop() can throw error if given index is out of range, so check size before calling it
if len(listOfnum) >= 20:
    listOfnum.pop(20)
else:    
    print("Index Out of Range")   

or Use try / except
# pop() can throw error if given index is out of range, so use try / except
try :
    listOfnum.pop(20)
except IndexError:
    print("Index Out of Range")   

Remove an element from List by del

In python del is a keyword and can be used to delete the element in list by index i.e.

del listOfNum[2]

It will delete the element at index 2 in list.

If del list[index] is called on an index that is out of the boundary of List then it will generate a runtime error.
Therefore check size of list before calling del i.e.

# del list[index]  can throw error if given index is out of range, so check size before calling it
if len(listOfnum) >= 20:
    del listOfnum[20]
else:    
    print("Index Out of Range")   

or Use try / except
# del list[index] can throw error if given index is out of range, so use try / except
try :
    del listOfnum[20]
except IndexError:
    print("Index Out of Range")

Complete example is as follows,
def main():
    
    # List of numbers
    listOfnum = [12, 44, 56, 45, 34, 3, 56, 4, 33, 44, 56]
    
    '''
    Remove an element from List by value using list.remove()
    '''
    print("*****list.remove()*****")
    
    print("Original List : " , listOfnum)
    
    # Remove first occurrence of 56 from List 
    listOfnum.remove(56)
    
    print("Modified List : " , listOfnum)
    
    
    # If given element doesn't exists in list, then remove() can throw Error
    # Therefore use try / except while calling list.remove()
    try :
        listOfnum.remove(99)
    except ValueError:
        print("Given Element Not Found in List")        
        
    # Check if element exist in List, before removing
    if 99 in listOfnum:
        listOfnum.remove(99)
    else:
        print("Given Element Not Found in List")

    '''
    Remove an element from List by Index using list.pop()
    '''    
    print("*****list.pop()*****")
        
    # List of numbers
    listOfnum = [12, 44, 12, 56, 45, 34, 3, 56, 4, 33, 44, 56]
    
    print("Original List : ", listOfnum)
        
    # Remove the element at index 2 in list    
    value = listOfnum.pop(2)
    
    print("Deleted Element : ", value)
    print("Modified List : ", listOfnum)
    
    # Remove the last element from list   
    value = listOfnum.pop()
    print("Deleted Element : ", value)
    print("Modified List : ", listOfnum)
    
    # pop() can throw error if given index is out of range, so check size before calling it
    if len(listOfnum) >= 20:
        listOfnum.pop(20)
    else:    
        print("Index Out of Range")   
    
    # pop() can throw error if given index is out of range, so use try / except
    try :
        listOfnum.pop(20)
    except IndexError:
        print("Index Out of Range")   
    
    
    
    print("*****del list[index]*****")
    
    
    '''
        Remove an element from List by del
    '''
    
    listOfnum = [12, 44, 56, 45, 34, 3, 4, 33, 44]
     
    print("Original List : ", listOfnum)
    
    # Delete element at index 2
    del listOfnum[2]
    
    print("Modified List : ", listOfnum)
    

    # del list[index]  can throw error if given index is out of range, so check size before calling it
    if len(listOfnum) >= 20:
        del listOfnum[20]
    else:    
        print("Index Out of Range")   
    
    # del list[index] can throw error if given index is out of range, so use try / except
    try :
        del listOfnum[20]
    except IndexError:
        print("Index Out of Range")
           
if __name__ == '__main__':
    main()

Output:
*****list.remove()*****
Original List :  [12, 44, 56, 45, 34, 3, 56, 4, 33, 44, 56]
Modified List :  [12, 44, 45, 34, 3, 56, 4, 33, 44, 56]
Given Element Not Found in List
Given Element Not Found in List
*****list.pop()*****
Original List :  [12, 44, 12, 56, 45, 34, 3, 56, 4, 33, 44, 56]
Deleted Element :  12
Modified List :  [12, 44, 56, 45, 34, 3, 56, 4, 33, 44, 56]
Deleted Element :  56
Modified List :  [12, 44, 56, 45, 34, 3, 56, 4, 33, 44]
Index Out of Range
Index Out of Range
*****del list[index]*****
Original List :  [12, 44, 56, 45, 34, 3, 4, 33, 44]
Modified List :  [12, 44, 45, 34, 3, 4, 33, 44]
Index Out of Range
Index Out of Range