python - One-liner to remove duplicates, keep ordering of list -


this question has answer here:

i have following list:

['herb', 'alec', 'herb', 'don']

i want remove duplicates while keeping order, :

['herb', 'alec', 'don']

here how verbosely:

l_new = [] item in l_old:     if item not in l_new: l_new.append(item)

is there way in single line?

you use ordereddict, suggest sticking for-loop.

>>> collections import ordereddict >>> data = ['herb', 'alec', 'herb', 'don'] >>> list(ordereddict.fromkeys(data)) ['herb', 'alec', 'don']

just reiterate: seriously suggest sticking for-loop approach, , use set keep track of seen items:

>>> data = ['herb', 'alec', 'herb', 'don'] >>> seen = set() >>> unique_data = [] >>> x in data: ...     if x not in seen: ...         unique_data.append(x) ...         seen.add(x) ... >>> unique_data ['herb', 'alec', 'don']

and in case want wacky (seriously don't this):

>>> [t[0] t in sorted(dict(zip(reversed(data), range(len(data), -1, -1))).items(), key=lambda t:t[1])] ['herb', 'alec', 'don']

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