Sure, naming is hard, but avoid "l", "I", "O", "o".
Very short variable names (including "ns" and "n") are always some kind of disturbance when reading code, especially when the variable lasts longer than one screen of code – one has to memorize the meaning. They sometimes have a point, e.g. in mathematical code like this one. But variables like "l" and "O" are bad for a further reason, as they can not easily be distinguished from the numbers. See also the Python style guide: https://peps.python.org/pep-0008/#names-to-avoid
Very short variable names (including "ns" and "n") are always some kind of disturbance when reading code, especially when the variable lasts longer than one screen of code – one has to memorize the meaning. They sometimes have a point, e.g. in mathematical code like this one. But variables like "l" and "O" are bad for a further reason, as they can not easily be distinguished from the numbers. See also the Python style guide: https://peps.python.org/pep-0008/#names-to-avoid