How to find common occurrences of dictionary in a list of list of dictionaries












1















I have a list of list of dictionaries and I want to find the common dictionaries between the two list.



Eg:



dict_list = [[{'1' : 1,'2' : 2, '3' :3}, {'6' : 6,'5' : 5, '4' : 4}],  
[{'1' : 1,'2' : 2, '3' :3}, {'7' : 7,'8' : 8, '9' : 9}]]


The result should be [{'1' : 1,'2' : 2, '3' :3}]



I tried using set intersections but dictionaries are unhashable in python.



How to solve this?










share|improve this question




















  • 5





    [dict(k) for k,v in Counter(tuple(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]

    – Chris_Rands
    Nov 14 '18 at 11:00






  • 1





    @Chris_Rands I didn't see your solution at all when I posted mine. Do you want me to remove it?

    – RoadRunner
    Nov 14 '18 at 11:13






  • 2





    @RoadRunner no don't remove it, people do have the same idea sometimes, thanks for asking though :)

    – Chris_Rands
    Nov 14 '18 at 11:18











  • after converting a list of dict to list of tuple, he can use set.intersection too, I guess

    – khelili miliana
    Nov 14 '18 at 11:21


















1















I have a list of list of dictionaries and I want to find the common dictionaries between the two list.



Eg:



dict_list = [[{'1' : 1,'2' : 2, '3' :3}, {'6' : 6,'5' : 5, '4' : 4}],  
[{'1' : 1,'2' : 2, '3' :3}, {'7' : 7,'8' : 8, '9' : 9}]]


The result should be [{'1' : 1,'2' : 2, '3' :3}]



I tried using set intersections but dictionaries are unhashable in python.



How to solve this?










share|improve this question




















  • 5





    [dict(k) for k,v in Counter(tuple(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]

    – Chris_Rands
    Nov 14 '18 at 11:00






  • 1





    @Chris_Rands I didn't see your solution at all when I posted mine. Do you want me to remove it?

    – RoadRunner
    Nov 14 '18 at 11:13






  • 2





    @RoadRunner no don't remove it, people do have the same idea sometimes, thanks for asking though :)

    – Chris_Rands
    Nov 14 '18 at 11:18











  • after converting a list of dict to list of tuple, he can use set.intersection too, I guess

    – khelili miliana
    Nov 14 '18 at 11:21
















1












1








1








I have a list of list of dictionaries and I want to find the common dictionaries between the two list.



Eg:



dict_list = [[{'1' : 1,'2' : 2, '3' :3}, {'6' : 6,'5' : 5, '4' : 4}],  
[{'1' : 1,'2' : 2, '3' :3}, {'7' : 7,'8' : 8, '9' : 9}]]


The result should be [{'1' : 1,'2' : 2, '3' :3}]



I tried using set intersections but dictionaries are unhashable in python.



How to solve this?










share|improve this question
















I have a list of list of dictionaries and I want to find the common dictionaries between the two list.



Eg:



dict_list = [[{'1' : 1,'2' : 2, '3' :3}, {'6' : 6,'5' : 5, '4' : 4}],  
[{'1' : 1,'2' : 2, '3' :3}, {'7' : 7,'8' : 8, '9' : 9}]]


The result should be [{'1' : 1,'2' : 2, '3' :3}]



I tried using set intersections but dictionaries are unhashable in python.



How to solve this?







python dictionary






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 14 '18 at 10:57









Zlytherin

1,7071728




1,7071728










asked Nov 14 '18 at 10:54









Perseus14Perseus14

302316




302316








  • 5





    [dict(k) for k,v in Counter(tuple(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]

    – Chris_Rands
    Nov 14 '18 at 11:00






  • 1





    @Chris_Rands I didn't see your solution at all when I posted mine. Do you want me to remove it?

    – RoadRunner
    Nov 14 '18 at 11:13






  • 2





    @RoadRunner no don't remove it, people do have the same idea sometimes, thanks for asking though :)

    – Chris_Rands
    Nov 14 '18 at 11:18











  • after converting a list of dict to list of tuple, he can use set.intersection too, I guess

    – khelili miliana
    Nov 14 '18 at 11:21
















  • 5





    [dict(k) for k,v in Counter(tuple(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]

    – Chris_Rands
    Nov 14 '18 at 11:00






  • 1





    @Chris_Rands I didn't see your solution at all when I posted mine. Do you want me to remove it?

    – RoadRunner
    Nov 14 '18 at 11:13






  • 2





    @RoadRunner no don't remove it, people do have the same idea sometimes, thanks for asking though :)

    – Chris_Rands
    Nov 14 '18 at 11:18











  • after converting a list of dict to list of tuple, he can use set.intersection too, I guess

    – khelili miliana
    Nov 14 '18 at 11:21










5




5





[dict(k) for k,v in Counter(tuple(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]

– Chris_Rands
Nov 14 '18 at 11:00





[dict(k) for k,v in Counter(tuple(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]

– Chris_Rands
Nov 14 '18 at 11:00




1




1





@Chris_Rands I didn't see your solution at all when I posted mine. Do you want me to remove it?

– RoadRunner
Nov 14 '18 at 11:13





@Chris_Rands I didn't see your solution at all when I posted mine. Do you want me to remove it?

– RoadRunner
Nov 14 '18 at 11:13




2




2





@RoadRunner no don't remove it, people do have the same idea sometimes, thanks for asking though :)

– Chris_Rands
Nov 14 '18 at 11:18





@RoadRunner no don't remove it, people do have the same idea sometimes, thanks for asking though :)

– Chris_Rands
Nov 14 '18 at 11:18













after converting a list of dict to list of tuple, he can use set.intersection too, I guess

– khelili miliana
Nov 14 '18 at 11:21







after converting a list of dict to list of tuple, he can use set.intersection too, I guess

– khelili miliana
Nov 14 '18 at 11:21














1 Answer
1






active

oldest

votes


















3














A list comprehension could work here:



>>> [x for x in dict_list[0] if x in dict_list[1]]
[{'1': 1, '2': 2, '3': 3}]


But this is not a very general solution, since it assumes only two nested lists are exististent.



A more general solution would be to count the occurences with collections.Counter(), and storing the dictionary items() with hashable/immutable types such as frozenset() or tuple(). Then all you need to do is filter the occurences that count more than 1.



Example:



>>> from itertools import chain
>>> from collections import Counter
>>> [dict(k) for k, v in Counter(frozenset(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]
[{'1': 1, '2': 2, '3': 3}]


Which is very similar to the approach @Chris_Rands posted in the comments.






share|improve this answer





















  • 1





    The main point here is that even though dictionaries are not hashable they are comparable. More about comparing dictionaries in python.

    – sophros
    Nov 14 '18 at 11:01













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1 Answer
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oldest

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1 Answer
1






active

oldest

votes









active

oldest

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active

oldest

votes









3














A list comprehension could work here:



>>> [x for x in dict_list[0] if x in dict_list[1]]
[{'1': 1, '2': 2, '3': 3}]


But this is not a very general solution, since it assumes only two nested lists are exististent.



A more general solution would be to count the occurences with collections.Counter(), and storing the dictionary items() with hashable/immutable types such as frozenset() or tuple(). Then all you need to do is filter the occurences that count more than 1.



Example:



>>> from itertools import chain
>>> from collections import Counter
>>> [dict(k) for k, v in Counter(frozenset(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]
[{'1': 1, '2': 2, '3': 3}]


Which is very similar to the approach @Chris_Rands posted in the comments.






share|improve this answer





















  • 1





    The main point here is that even though dictionaries are not hashable they are comparable. More about comparing dictionaries in python.

    – sophros
    Nov 14 '18 at 11:01


















3














A list comprehension could work here:



>>> [x for x in dict_list[0] if x in dict_list[1]]
[{'1': 1, '2': 2, '3': 3}]


But this is not a very general solution, since it assumes only two nested lists are exististent.



A more general solution would be to count the occurences with collections.Counter(), and storing the dictionary items() with hashable/immutable types such as frozenset() or tuple(). Then all you need to do is filter the occurences that count more than 1.



Example:



>>> from itertools import chain
>>> from collections import Counter
>>> [dict(k) for k, v in Counter(frozenset(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]
[{'1': 1, '2': 2, '3': 3}]


Which is very similar to the approach @Chris_Rands posted in the comments.






share|improve this answer





















  • 1





    The main point here is that even though dictionaries are not hashable they are comparable. More about comparing dictionaries in python.

    – sophros
    Nov 14 '18 at 11:01
















3












3








3







A list comprehension could work here:



>>> [x for x in dict_list[0] if x in dict_list[1]]
[{'1': 1, '2': 2, '3': 3}]


But this is not a very general solution, since it assumes only two nested lists are exististent.



A more general solution would be to count the occurences with collections.Counter(), and storing the dictionary items() with hashable/immutable types such as frozenset() or tuple(). Then all you need to do is filter the occurences that count more than 1.



Example:



>>> from itertools import chain
>>> from collections import Counter
>>> [dict(k) for k, v in Counter(frozenset(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]
[{'1': 1, '2': 2, '3': 3}]


Which is very similar to the approach @Chris_Rands posted in the comments.






share|improve this answer















A list comprehension could work here:



>>> [x for x in dict_list[0] if x in dict_list[1]]
[{'1': 1, '2': 2, '3': 3}]


But this is not a very general solution, since it assumes only two nested lists are exististent.



A more general solution would be to count the occurences with collections.Counter(), and storing the dictionary items() with hashable/immutable types such as frozenset() or tuple(). Then all you need to do is filter the occurences that count more than 1.



Example:



>>> from itertools import chain
>>> from collections import Counter
>>> [dict(k) for k, v in Counter(frozenset(x.items()) for x in chain.from_iterable(dict_list)).items() if v > 1]
[{'1': 1, '2': 2, '3': 3}]


Which is very similar to the approach @Chris_Rands posted in the comments.







share|improve this answer














share|improve this answer



share|improve this answer








edited Nov 19 '18 at 15:23

























answered Nov 14 '18 at 10:59









RoadRunnerRoadRunner

11.2k31340




11.2k31340








  • 1





    The main point here is that even though dictionaries are not hashable they are comparable. More about comparing dictionaries in python.

    – sophros
    Nov 14 '18 at 11:01
















  • 1





    The main point here is that even though dictionaries are not hashable they are comparable. More about comparing dictionaries in python.

    – sophros
    Nov 14 '18 at 11:01










1




1





The main point here is that even though dictionaries are not hashable they are comparable. More about comparing dictionaries in python.

– sophros
Nov 14 '18 at 11:01







The main point here is that even though dictionaries are not hashable they are comparable. More about comparing dictionaries in python.

– sophros
Nov 14 '18 at 11:01




















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