How to remove duplicate tuples from a list in python?

Question

I have a list that contains list of tuples as follows.

mylist = [[\'xxx\', 879], [\'yyy\', 315], [\'xxx\', 879], [\'zzz\', 171], [\'yyy\', 315]]

Answer 1

It seems like you want to preserve order. In that case you can keep a set that keeps track of what lists have been added.

Here is an example:

mylist = [['xxx', 879], ['yyy', 315], ['xxx', 879], ['zzz', 171], ['yyy', 315]]

# set that keeps track of what elements have been added
seen = set()

no_dups = []
for lst in mylist:

    # convert to hashable type
    current = tuple(lst)

    # If element not in seen, add it to both
    if current not in seen:
        no_dups.append(lst)
        seen.add(current)

print(no_dups)

Which Outputs:

[['xxx', 879], ['yyy', 315], ['zzz', 171]]

Note: Since lists are not hashable, you can add tuples instead to the seen set.