How to check if all elements in a tuple or list are in another?

Question

For example, I want to check every elements in tuple (1, 2) are in tuple (1, 2, 3, 4, 5). I don't think use loop is a good way to do it, I think it could be done in one line.

Underachieve

Are the tuples sorted? – Pechora

Are you only asking about the case where all elements are integers? and moreover, sorted in-order? (so that the order of the tuple doesn't matter?) Do you want to return True or False for testing (2,1) in (5,3,1,4,2)? Can you please show several more examples with expect output value? – Seep

And if the all elements are contiguous integers, you can use a data structure like slice which only needs to test its lower- and upper-bound (start, stop and step, you don't even need a tuple/set. Or itertools.islice – Seep

Answer 1

You can use set.issubset or set.issuperset to check if every element in one tuple or list is in other.

>>> tuple1 = (1, 2)
>>> tuple2 = (1, 2, 3, 4, 5)
>>> set(tuple1).issubset(tuple2)
True
>>> set(tuple2).issuperset(tuple1)
True

Rotl

Answer 2

I think you want this: ( Use all )

>>> all(i in (1,2,3,4,5) for i in (1,2))
True 

Steakhouse

Answer 3

Since your question is specifically targeted at tuples/lists and not sets, I would assume you include cases where elements are repeated and the number of repetition matters. For example (1, 1, 3) is in (0, 1, 1, 2, 3), but (1, 1, 3, 3) is not.

import collections

def contains(l1, l2):
    l1_cnt = set(collections.Counter(l1).items())
    l2_cnt = set(collections.Counter(l2).items())

    return l2_cnt <= l1_cnt

# contains((0, 1, 2, 3, 4, 5), (1, 2)) returns True
# contains((0, 1, 1, 2, 3), (1, 1, 3)) returns True
# contains((0, 1, 1, 2, 3), (1, 1, 3, 3)) returns False

Mandrill

Answer 4

Another alternative would be to create a simple function when the set doesn't come to mind.

def tuple_containment(a,b):
    ans = True
    for i in iter(b):
        ans &= i in a
    return ans

Now simply test them

>>> tuple_containment ((1,2,3,4,5), (1,2))
True
>>> tuple_containment ((1,2,3,4,5), (2,6))
False

Disclaim

And I clearly mentioned that mine is when the obvious doesn't come to mind – Disclaim

What does tuple_checker do? Check for equality, containment, or just whether they are tuples? – Pechora