Remove All the Elements That Occur in One List from Another

remove elements of one list from another list python

I would use a counter of the elements to be removed.

So, something like

from collections import Counter 

data = [1, 2, 2, 3, 3, 3]
to_be_removed = [1, 2, 3, 3] # notice the extra 3

counts = Counter(to_be_removed)

new_data = []
for x in data:
    if counts[x]:
        counts[x] -= 1
    else:
        new_data.append(x)

print(new_data)

This solution is linear time / space. If you actually need to modify the list (which is code-smell, IMO), you would require quadratic time

Note, consider if you actually just want a multiset - i.e. you could just be working with counters all along, consider:

>>> Counter(data) - Counter(to_be_removed)
Counter({2: 1, 3: 1})

Remove item from one list if NOT in another list?

Assuming playing is a list of strings corresponding to player names:

bedwarsPoints = [i for i in bedwarsPoints if i[0] in playing]

remove elements in one list present in another list

Use list comprehension:

>>> list1 = ['paste', 'text', 'text', 'here', 'here', 'here', 'my', 'i', 'i', 'me', 'me']
>>> list2 = ["i","me"]
>>> list3 = [item for item in list1 if item not in list2]
>>> list3
['paste', 'text', 'text', 'here', 'here', 'here', 'my']

NOTE: Lookups in lists are O(n), consider making a set from list2 instead - lookups in sets are O(1).

Remove elements from list that is in another list while keeping duplicates

you need a little bit more complex loops:

l1 = ['a', 'b', 'b', 'a', 'c', 'c', 'a']
l2 = ['c', 'b']
l3=[]
for item in l1:
    if item in l2:
        l2.remove(item)
    else:
        l3.append(item)
>>>l3
['a', 'b', 'a', 'c', 'a']

python remove elements of list from another list WITH MULTIPLE OCCURRENCES of items in both

Here is a non list comprehension version for those new to Python

listA = [1, 1, 3, 5, 5, 5, 7]
listB = [1, 2, 5, 5, 7]
for i in listB:
    if i in listA:
        listA.remove(i)

print listA

How to move multiple elements from one list to another and delete from first list

Generally speaking, you shouldn't try to modify a list as you're iterating over it, as the memory is shifting while you're trying to access it (the mapping between the elements in list_1 and to_move may not be easily retained if you remove elements from list_1 as well).

Instead, use a list comprehension:

list_1 = [1, 2, 3, 4]
to_move = [True, False, False, True]

list_2 = [elem for index, elem in enumerate(list_1) if to_move[index]]
list_1 = [elem for index, elem in enumerate(list_1) if not to_move[index]]

print(list_1, list_2) # Prints [2, 3] [1, 4]

python remove elements from one list based on indices from another list

To do that, you can use the .pop() method.

position = [1, 0 ,0 ]
values = [2, 6, 1]

for idx in position:
    values.pop(idx)

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