I have a list of lists and I'd like to remove all nested lists which contain any of multiple values.
list_of_lists = [[1,2], [3,4], [5,6]]
indices = [i for i,val in enumerate(list_of_lists) if (1,6) in val]
print(indices)
[0]
I'd like a lists of indices where this conditions is so that I can:
del list_of_lists[indices]
To remove all nested lists which contain certain values. I'm guessing the problem is where I try to check against multiple values (1,6) as using either 1 or 6 works.
You could use a set operation:
if not {1, 6}.isdisjoint(val)
A set is disjoint if none of the values appear in the other sequence or set:
>>> {1, 6}.isdisjoint([1, 2])
False
>>> {1, 6}.isdisjoint([3, 4])
True
Or just test both values:
if 1 in val or 6 in val
I'd not build a list of indices. Just rebuild the list and filter out anything you don't want in the new list:
list_of_lists[:] = [val for val in list_of_lists if {1, 6}.isdisjoint(val)]
By assigning to the [:] whole slice you replace all indices in list_of_lists, updating the list object in-place:
>>> list_of_lists = [[1, 2], [3, 4], [5, 6]]
>>> another_ref = list_of_lists
>>> list_of_lists[:] = [val for val in list_of_lists if {1, 6}.isdisjoint(val)]
>>> list_of_lists
[[3, 4]]
>>> another_ref
[[3, 4]]
See What is the difference between slice assignment that slices the whole list and direct assignment? for more detail on what assigning to a slice does.