Remove duplicate items from lists in Python lists

I want to remove duplicate items from lists in sublists on Python.

Exemple :

• myList = [[1,2,3], [4,5,6,3], [7,8,9], [0,2,4]]

to

• myList = [[1,2,3], [4,5,6], [7,8,9], [0]]

I tried with this code :

myList = [[1,2,3],[4,5,6,3],[7,8,9], [0,2,4]]
 
nbr = []

for x in myList:
    for i in x:     
        if i not in nbr:
            nbr.append(i)
        else:
            x.remove(i)
    

But some duplicate items are not deleted.

Like this : [[1, 2, 3], [4, 5, 6], [7, 8, 9], [0, 4]]

I still have the number 4 that repeats.

>Solution :

You iterate over a list that you are also modifying:

...
    for i in x:
        ...
        x.remove(i)

That means that it may skip an element on next iteration.

The solution is to create a shallow copy of the list and iterate over that while modifying the original list:

...
    for i in x.copy():
        ...
        x.remove(i)