how to get all proper subsets of a set in python

main.py
def get_subsets(s):
    """Returns a list of all subsets of set s"""
    if not s:
        return [[]]
    x = s.pop()
    subsets = get_subsets(s)
    new_subsets = []
    for subset in subsets:
        new_subsets.append(subset + [x])
    return subsets + new_subsets

def get_proper_subsets(s):
    """Returns a list of all proper subsets of set s"""
    subsets = get_subsets(s)
    return [subset for subset in subsets if subset != s]
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main.py
>>> s = set([1, 2, 3])
>>> get_proper_subsets(s)
[[1], [2], [3], [1, 2], [1, 3], [2, 3]]
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