Difference between del, remove, and pop on lists

Many good explanations are here but I will try my best to simplify more.

Among all these methods, remove & pop are postfix while delete is prefix.

remove(): Is used to remove first occurrence of element.
remove(n) => first occurrence of n in the list.

>>> a = [0, 2, 3, 2, 1, 4, 6, 5, 7]
>>> a.remove(2)   # where i = 2
>>> a
[0, 3, 2, 1, 4, 6, 5, 7]

pop(): Is used to remove element ...

• if no index is specified:
  pop() => from end of list

>>> a.pop()
>>> a
[0, 3, 2, 1, 4, 6, 5]

• if an index is specified:
  pop(index) => of index

>>> a.pop(2)
>>> a
[0, 3, 1, 4, 6, 5]

WARNING: Dangerous Method Ahead

del(): It's a prefix method.

Keep an eye on two different syntaxes for same method: with [] and without. It possesses power to:

• Delete index
  del a[index] => used to delete by index and its associated value just like pop.

>>> del a[1]
>>> a
[0, 1, 4, 6, 5]

• Delete values in range [index_1:index_N]:
  del a[0:3] => multiple values in range.

>>> del a[0:3]
>>> a
[6, 5]

• Last but not least, to delete whole list in one shot.
  del (a) => as said above.

>>> del (a)
>>> a
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'a' is not defined

Hope this clarifies the confusion.

Here is a detailed answer.

del can be used for any class object whereas pop and remove and bounded to specific classes.

For del

Here are some examples

>>> a = 5
>>> b = "this is string"
>>> c = 1.432
>>> d = myClass()

>>> del c
>>> del a, b, d   # we can use comma separated objects

We can override __del__ method in user-created classes.

Specific uses with list

>>> a = [1, 4, 2, 4, 12, 3, 0]
>>> del a[4]
>>> a
[1, 4, 2, 4, 3, 0]

>>> del a[1: 3]   # we can also use slicing for deleting range of indices
>>> a
[1, 4, 3, 0]

For pop

pop takes the index as a parameter and removes the element at that index

Unlike del, pop when called on list object returns the value at that index

>>> a = [1, 5, 3, 4, 7, 8]
>>> a.pop(3)  # Will return the value at index 3
4
>>> a
[1, 5, 3, 7, 8]

For remove

remove takes the parameter value and remove that value from the list.

If multiple values are present will remove the first occurrence

Note: Will throw ValueError if that value is not present

>>> a = [1, 5, 3, 4, 2, 7, 5]
>>> a.remove(5)  # removes first occurence of 5
>>> a
[1, 3, 4, 2, 7, 5]
>>> a.remove(5)
>>> a
[1, 3, 4, 2, 7]

Hope this answer is helpful.

The remove operation on a list is given a value to remove. It searches the list to find an item with that value and deletes the first matching item it finds. It is an error if there is no matching item, raises a ValueError.

>>> x = [1, 0, 0, 0, 3, 4, 5]
>>> x.remove(4)
>>> x
[1, 0, 0, 0, 3, 5]
>>> del x[7]
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    del x[7]
IndexError: list assignment index out of range

The del statement can be used to delete an entire list. If you have a specific list item as your argument to del (e.g. listname[7] to specifically reference the 8th item in the list), it'll just delete that item. It is even possible to delete a "slice" from a list. It is an error if there index out of range, raises a IndexError.

>>> x = [1, 2, 3, 4]
>>> del x[3]
>>> x
[1, 2, 3]
>>> del x[4]
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    del x[4]
IndexError: list assignment index out of range

The usual use of pop is to delete the last item from a list as you use the list as a stack. Unlike del, pop returns the value that it popped off the list. You can optionally give an index value to pop and pop from other than the end of the list (e.g listname.pop(0) will delete the first item from the list and return that first item as its result). You can use this to make the list behave like a queue, but there are library routines available that can provide queue operations with better performance than pop(0) does. It is an error if there index out of range, raises a IndexError.

>>> x = [1, 2, 3] 
>>> x.pop(2) 
3 
>>> x 
[1, 2]
>>> x.pop(4)
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    x.pop(4)
IndexError: pop index out of range

See collections.deque for more details.

Remove basically works on the value . Delete and pop work on the index

Remove basically removes the first matching value. Delete deletes the item from a specific index Pop basically takes an index and returns the value at that index. Next time you print the list the value doesnt appear.