python filter list of dictionaries based on key value

Solution 1:

You can try a list comp

>>> exampleSet = [{'type':'type1'},{'type':'type2'},{'type':'type2'}, {'type':'type3'}]
>>> keyValList = ['type2','type3']
>>> expectedResult = [d for d in exampleSet if d['type'] in keyValList]
>>> expectedResult
[{'type': 'type2'}, {'type': 'type2'}, {'type': 'type3'}]

Another way is by using filter

>>> list(filter(lambda d: d['type'] in keyValList, exampleSet))
[{'type': 'type2'}, {'type': 'type2'}, {'type': 'type3'}]

Solution 2:

Use filter, or if the number of dictionaries in exampleSet is too high, use ifilter of the itertools module. It would return an iterator, instead of filling up your system's memory with the entire list at once:

from itertools import ifilter
for elem in ifilter(lambda x: x['type'] in keyValList, exampleSet):
    print elem