Check a list of lists for a specific value in Python?

Question

I have

list_of_lists = [ ['a', 'b', 'c'] , ['b','c'] , ['c'] ]

and I want to determine whether or not

'd'

is a member of my list of lists. How do I go about doing that in Python?

I would just use a for loop: `any('d' in sub for sub in list_of_lists)` — Akavall, Oct 28 '15 at 01:35
Why are there ***answers*** in the comment boxes above? Surely a better place to put them would be in the ***answer*** boxes below :-) — paxdiablo, Oct 28 '15 at 01:42

score 0 · Accepted Answer · answered Oct 28 '15 at 01:43

The precise answer to your question (whether 'd' is a member of my list of lists) is

'd' in list_of_lists

But I suspect your question is just poorly worded

If your question was whether 'd' is a member of one of the items of list_of_lists, then the answer is

any('d' in lst for lst in list_of_lists)

score 0 · Answer 2 · answered Oct 28 '15 at 08:57

we can define a function, so it can handle arbitrary nested list.

def flatten(container):
    for item in container:
        if isinstance(item, list):
           for inner_item in flatten(item):
               yield inner_item
        else:
           yield item

>>> 'd' in flatten([['a', 'b', 'c'], ['b','c'], ['c']])
False
>>> 'd' in flatten([['a', 'b', 'c'], ['b','c', ['d']], ['c']])
True

Check a list of lists for a specific value in Python?

2 Answers2