Is there a simple way to delete a list element by value

0 votes

want to remove a value from a list if it exists in the list (which it may not).

a = [1, 2, 3, 4]
b = a.index(6)

del a[b]
print(a)

The above case (in which it does not exist) shows the following error:

Traceback (most recent call last):
  File "D:\zjm_code\a.py", line 6, in <module>
    b = a.index(6)
ValueError: list.index(x): x not in list

So I have to do this:

a = [1, 2, 3, 4]

try:
    b = a.index(6)
    del a[b]
except:
    pass

print(a)

But is there not a simpler way to do this?

Dec 28, 2020 in Python by Roshni
• 10,480 points
757 views

3 answers to this question.

0 votes

To remove an element's first occurrence in a list, simply use list.remove:

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

Mind that it does not remove all occurrences of your element. Use a list comprehension for that.

>>> a = [10, 20, 30, 40, 20, 30, 40, 20, 70, 20]
>>> a = [x for x in a if x != 20]
>>> print(a)
[10, 30, 40, 30, 40, 70]
answered Dec 28, 2020 by Gitika
• 65,770 points
0 votes

The effects of the three different methods to remove an element from a list:

remove removes the first matching value, not a specific index:

>>> a = [0, 2, 3, 2]
>>> a.remove(2)
>>> a
[0, 3, 2]

del removes the item at a specific index:

>>> a = [9, 8, 7, 6]
>>> del a[1]
>>> a
[9, 7, 6]

and pop removes the item at a specific index and returns it.

>>> a = [4, 3, 5]
>>> a.pop(1)
3
>>> a
[4, 5]

Their error modes are different too:

>>> a = [4, 5, 6]
>>> a.remove(7)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: list.remove(x): x not in list
>>> del a[7]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IndexError: list assignment index out of range
>>> a.pop(7)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IndexError: pop index out of range
answered Dec 28, 2020 by Reshma
0 votes

There are three ways in which you can Remove elements from List:

  1. Using the remove() method.
  2. Using the list object's pop() method.
  3. Using the del operator.

In Pythonlist 's methods clear() , pop() , and remove() are used to remove items (elements) from a list. It is also possible to delete items using del statement by specifying a position or range with an index or slice.

answered Dec 28, 2020 by Thomas Walenta

Related Questions In Python

0 votes
1 answer

Is there a way to list out in-built variables and functions of Python?

The in-built variables and functions are defined ...READ MORE

answered May 14, 2019 in Python by Junaid
2,241 views
0 votes
1 answer

Is there a way to loop between 0 and 1 by 0.1 in python?

You can use the linespace function. It ...READ MORE

answered May 28, 2019 in Python by Olly
3,120 views
0 votes
1 answer

Is there a way to store this text in a list using selenium (python)

Try using this code snippet to resolve ...READ MORE

answered Aug 24, 2020 in Python by Carlos
1,595 views
0 votes
1 answer

Deleting a list element by value

Use the remove() function: >>> p = [1, ...READ MORE

answered May 12, 2018 in Python by Hamartia's Mask
• 1,580 points
614 views
0 votes
2 answers
+1 vote
2 answers

how can i count the items in a list?

Syntax :            list. count(value) Code: colors = ['red', 'green', ...READ MORE

answered Jul 7, 2019 in Python by Neha
• 330 points

edited Jul 8, 2019 by Kalgi 4,463 views
0 votes
1 answer
0 votes
1 answer

How to remove an element from a list by index?

Use del and specify the index of the element ...READ MORE

answered Dec 18, 2020 in Python by Gitika
• 65,770 points
788 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP