How to remove specific element from an array using python

Question

I want to write something that removes a specific element from an array. I know that I have to for loop through the array to find the element that matches the c

Answer 1

Your for loop is not right, if you need the index in the for loop use:

for index, item in enumerate(emails):
    # whatever (but you can't remove element while iterating)

In your case, Bogdan solution is ok, but your data structure choice is not so good. Having to maintain these two lists with data from one related to data from the other at same index is clumsy.

A list of tupple (email, otherdata) may be better, or a dict with email as key.

Answer 2

Using filter() and lambda would provide a neat and terse method of removing unwanted values:

newEmails = list(filter(lambda x : x != 'something@something.com', emails))

This does not modify emails. It creates the new list newEmails containing only elements for which the anonymous function returned True.

Answer 3

There is an alternative solution to this problem which also deals with duplicate matches.

We start with 2 lists of equal length: emails, otherarray. The objective is to remove items from both lists for each index i where emails[i] == 'something@something.com'.

This can be achieved using a list comprehension and then splitting via zip:

emails = ['abc@def.com', 'something@something.com', 'ghi@jkl.com']
otherarray = ['some', 'other', 'details']

from operator import itemgetter

res = [(i, j) for i, j in zip(emails, otherarray) if i!= 'something@something.com']
emails, otherarray = map(list, map(itemgetter(0, 1), zip(*res)))

print(emails)      # ['abc@def.com', 'ghi@jkl.com']
print(otherarray)  # ['some', 'details']

Answer 4

If you want to delete the index of array:

Use array_name.pop(index_no.)

ex:-

>>> arr = [1,2,3,4]
>>> arr.pop(2)
>>>arr
[1,2,4]

If you want to delete a particular string/element from the array then

>>> arr1 = ['python3.6' , 'python2' ,'python3']
>>> arr1.remove('python2')
>>> arr1
['python3.6','python3']

Answer 5

The sane way to do this is to use zip() and a List Comprehension / Generator Expression:

filtered = (
    (email, other) 
        for email, other in zip(emails, other_list) 
            if email == 'something@something.com')

new_emails, new_other_list = zip(*filtered)

Also, if your'e not using array.array() or numpy.array(), then most likely you are using [] or list(), which give you Lists, not Arrays. Not the same thing.

Answer 6

You don't need to iterate the array. Just:

>>> x = ['ala@ala.com', 'bala@bala.com']
>>> x
['ala@ala.com', 'bala@bala.com']
>>> x.remove('ala@ala.com')
>>> x
['bala@bala.com']

This will remove the first occurence that matches the string.

EDIT: After your edit, you still don't need to iterate over. Just do:

index = initial_list.index(item1)
del initial_list[index]
del other_list[index]