Python intersection of 2 lists of dictionaries

Question

I have 2 lists of dicts like

list1 = [{'count': 351, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'},
     {'count': 332, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'},
     {'count': 336, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'},
     {'count': 359, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'},
     {'count': 309, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'}]


list2 = [{'count': 359, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'},
     {'count': 351, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'},
     {'count': 381, 'evt_datetime': datetime.datetime(2015, 10, 22, 8, 45), 'att_value': 'red'}]

I am trying to get common dicts from both the list. My desired output to be exact matches of the keys and values of the dict.

[{'count': 359, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'},
     {'count': 351, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'}]

Can this done by python itself efficiently or would require lib like pandas?

Answer 1

Use list comprehension:

[x for x in list1 if x in list2]

This returns me this list for your data:

[{'count': 351, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'}, {'count': 359, 'evt_datetime': datetime.datetime(2015, 10, 23, 8, 45), 'att_value': 'red'}]