Python: Joining characters in sublists of list of lists

Question

I have a huge list of lists, this is a section of it:

[['cusA', 'zupT', 'rcnA', 'cusA', 'zupT', 'zupT']]

I did the following operation on the entire list of lists:

[list(x) for x in set(tuple(x) for x in my_list)]

because I would like to have unique information in the sublists. This returned the following:

[['c', 'u', 's', 'A'], ['r', 'c', 'n', 'A'], ['z', 'u', 'p', 'T']]

Which is great, since it did become unique, but now I need them to be in their original from, without being broken up character-by-character.

Is there any way to re-join them inside the sublists?

Answer 1

Instead of list(x) , use ''.join(x) .

But you can just put the strings themselves in a set instead of calling tuple: list(set(my_list)) .

Answer 2

as you already mentioned: you can join the strings:

print(''.join(['c', 'u', 's', 'A'])) # cusA

for your whole list you could do this:

lst = [['c', 'u', 's', 'A'], ['r', 'c', 'n', 'A'], ['z', 'u', 'p', 'T']]

str_lst = [''.join(item) for item in lst]
print(str_lst)  # ['cusA', 'rcnA', 'zupT']

note that there is no point in creating a list of single characters; a string itself behaves exactly like a list of characters (an immutable one, though); so you could directoy do this:

print(set(['cusA', 'zupT', 'rcnA', 'cusA', 'zupT', 'zupT']))
# {'zupT', 'cusA', 'rcnA'}
# if you need a list again instead of a set:
print(list(set(['cusA', 'zupT', 'rcnA', 'cusA', 'zupT', 'zupT'])))
# ['zupT', 'cusA', 'rcnA']

that will not preserve the order though...

Answer 3

If the ordering of the contents of the inner lists does not matter, you can turn them into a set, which is a an un-ordered collection of unique elements, and then turn that set back into a list:

result = [list(set(li)) for li in my_list]

Prints:

[['cusA', 'rcnA', 'zupT']]