How to remove an element from a list in python ?

Examples of how to remove an element from a list in python

Remove an element using del()

To remove an element for a given index, a solution is to use the function del:

>>> L1 = ['a','b','c','d','e','f']
>>> del L1[3]
>>> L1
['a', 'b', 'c', 'e', 'f']

Remove the last element

>>> del L1[-1]
>>> L1
['a', 'b', 'c', 'e']

Remove the first element

>>> L1 = ['a','b','c','d','e','f']
>>> del L1[0]
>>> L1
['b', 'c', 'd', 'e', 'f']

Remove for a range of indexes

>>> L1
['a', 'b', 'c', 'e']
>>> del L1[1:3]
>>> L1
['a', 'e']

Trying to remove an element with an index out of range will return the following message:

>>> del L1[7]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IndexError: list assignment index out of range

Remove an element for a given value

>>> l = ['a', 'b', 'c', 'd', 'a']
>>> while 'a' in l:
...     del l[l.index('a')]
... 
>>> l
['b', 'c', 'd']

Remove an element with remove()

To remove an element for a given value, another solution is to use the function remove (Note: this function only remove the first occurrence):

>>> l = ['a', 'b', 'c', 'd', 'a']
>>> l.remove('a')
>>> l
['b', 'c', 'd', 'a']

to remove all elements:

>>> l = ['a', 'b', 'c', 'd', 'a']
>>> while 'a' in l:
...     l.remove('a')
... 
>>> l
['b', 'c', 'd']

Remove an element with a for loop

It is also possible to filter a list in python using a for loop:

>>> l = ['a', 'b', 'c', 'd', 'a']
>>> l = [i for i in l if i != 'a']
>>> l
['b', 'c', 'd']

Remove all elements in a list

Remove all elements using del:

>>> l = ['a', 'b', 'c', 'd', 'a']
>>> del l[:]
>>> l
[]

using clear():

>>> l = ['a', 'b', 'c', 'd', 'a']
>>> l.clear()
>>> l
[]

References