Python syntax: mutating/reducing a defaultdict? -

i wasn't sure term is, have word_set in form of defaultdict [(word, value), ...] came function parsed raw data.

i have other functions: reduceval(word_set, min_val), reduceword(word_set, *args), etc removes pairs that: have value less min_val, have (word) in [args], respectively. pretty follow same structure, e.g.

def reduceval(word_set, value):     "returns word_set (k, v) pairs v > value)"     rtn_set = defaultdict()     (k, v) in word_set.items():         if v > value:             rtn_set.update({k:v})     return rtn_set 

i wondering if there more concise, or pythonic, way of expressing this, without building new rtn_set or maybe defining entire function

if learn use dict comprehensions don't need have separate functions of these different filters. instance, reduceval , reduceword replaced with:

# python 2.7+ {w: v w, v in word_set.items() if v > value} {w: v w, v in word_set.items() if w in args}  # python 2.6 , earlier dict((w, v) w, v in word_set.iteritems() if v > value) dict((w, v) w, v in word_set.iteritems() if w in args)