How can I verify if one list is a subset of another?

>>> a = [1, 3, 5]
>>> b = [1, 3, 5, 8]
>>> c = [3, 5, 9]
>>> set(a) <= set(b)
True
>>> set(c) <= set(b)
False

>>> a = ['yes', 'no', 'hmm']
>>> b = ['yes', 'no', 'hmm', 'well']
>>> c = ['sorry', 'no', 'hmm']
>>> 
>>> set(a) <= set(b)
True
>>> set(c) <= set(b)
False

Use set.issubset

Example:

a = {1,2}
b = {1,2,3}
a.issubset(b) # True

a = {1,2,4}
b = {1,2,3}
a.issubset(b) # False

The performant function Python provides for this is set.issubset. It does have a few restrictions that make it unclear if it's the answer to your question, however.

A list may contain items multiple times and has a specific order. A set does not. Additionally, sets only work on hashable objects.

Are you asking about subset or subsequence (which means you'll want a string search algorithm)? Will either of the lists be the same for many tests? What are the datatypes contained in the list? And for that matter, does it need to be a list?

Your other post intersect a dict and list made the types clearer and did get a recommendation to use dictionary key views for their set-like functionality. In that case it was known to work because dictionary keys behave like a set (so much so that before we had sets in Python we used dictionaries). One wonders how the issue got less specific in three hours.