如何从列表中删除子列表？

Question

I've got a big list of training_data with 50,000 samples. Every sample contains two sublists which contain two elements (sample, label).

I accidentally created another list inside the label item which has again two items.

ie)

                              main_list

                           _______|_______
                          |               |
                       sample           label(list)
                                     _____|_____
                                a(list)        b(list)

I want to remove 'b' sub-list from every example (50000). I hope I did explain it correctly. Save me.

Answer 1

If I understand correctly, try new_list = [ [x[0], x[1][0]] for x in main_list] . In any way, list comprehension will probably be enough to fix your problem...

Answer 2

I've tried to recreate your list hierarchy as follows:

a = ["w", "x"]
b = ["y", "z"]
label = [a, b]
sample = ["sample1", "sample2"]
main_list = [sample, label]

This gives us that

print(main_list)
[['sample1', 'sample2'], [['w', 'x'], [ 'y', 'z']]]

Then to remove b , you simply have to set

main_list = [main_list[0], main_list[1][0]] 

Does this achieve what you want?