Python: Check if one dictionary is a subset of another larger dictionary

Question

I\'m trying to write a custom filter method that takes an arbitrary number of kwargs and returns a list containing the elements of a database-like list that contain

Answer 1

My function for the same purpose, doing this recursively:

def dictMatch(patn, real):
    """does real dict match pattern?"""
    try:
        for pkey, pvalue in patn.iteritems():
            if type(pvalue) is dict:
                result = dictMatch(pvalue, real[pkey])
                assert result
            else:
                assert real[pkey] == pvalue
                result = True
    except (AssertionError, KeyError):
        result = False
    return result

In your example, dictMatch(d1, d2) should return True even if d2 has other stuff in it, plus it applies also to lower levels:

d1 = {'a':'2', 'b':{3: 'iii'}}
d2 = {'a':'2', 'b':{3: 'iii', 4: 'iv'},'c':'4'}

dictMatch(d1, d2)   # True

Notes: There could be even better solution which avoids the if type(pvalue) is dict clause and applies to even wider range of cases (like lists of hashes etc). Also recursion is not limited here so use at your own risk. ;)