CODEWITHSUNDEEP
pythonsublist
user3496062
user3496062

Reputation: 21

How do you clean up redundant values in a list of lists

Say I have a list of list X=[[0,0,0,3,4],[8,8,9,2,8,2]]

How do I make it so that each sublist will only contain a repeated number once:
Like this new list:

XNew=[[0,3,4],[8,9,2]]

Upvotes: 0

Views: 59

Answers (2)

Steinar Lima
Steinar Lima

Reputation: 7821

If you need to keep the order of your numbers, you can't use sets. This would keep the original order:

lst = [[0, 0, 0, 3, 4], [8, 8, 9, 2, 8, 2]]
new_lst = []

for sub_lst in lst:
    seen = set()
    new_sub = []
    for item in sub_lst:
        if item not in seen:
            new_sub.append(item)
            seen.add(item)
    new_lst.append(new_sub)

print new_lst # [[0, 3, 4], [8, 9, 2]]

Upvotes: 0

sshashank124
sshashank124

Reputation: 32189

You can use set for that:

new_x = [list(set(i)) for i in old_x]

Sets are a collection of unique elements and therefore create a set of unique values when a list of duplicate values is cast as a set. You can then convert the set back to a list and get the desired result.

Example

>>> old_x = [[0,0,0,3,4],[8,8,9,2,8,2]]
>>> new_x = [list(set(i)) for i in old_x]
>>> print new_x
[[0,3,4],[8,9,2]]

Upvotes: 5

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