1 liner 'pythonic' code that returns a set rather than a list

Question

I would like to do the following code, except in a neat 1-liner:

terms_set = set([])
for term in terms: 
    if index.has_key(term): 
        terms_set.add(index[term])

Is it possible to do? Must return a set.

Answer 1

You can use a set comprehension:

terms_set = {index[term] for term in terms if term in index}

Note that key in dict is preferred over dict.has_key, which was deprecated in Python 2 and is not available in Python 3.

Answer 2

terms_set = set(index[term] for term in terms if index.has_key(term))