'PyMongo aggregation function

Need solution of code which is aimed at finding out the total number of movies by genre. The code I am using is:

agg_result = movies_collection.aggregate(
[{"$match": {}},{"$group":
       {"_id":"$genres", 
        "Total movie count":{"$sum":1}
       }}
])
for i in agg_result:
    print(i)

I need movies by each genre but since uploaded csv file has multiple entries in genre field the sample output is coming wrong.

Sample output coming as: {'_id': 'Animation|Children|Comedy|Fantasy', 'Total movie count': 6} {'_id': 'Action|Drama|Horror|IMAX', 'Total movie count': 1}

mongodb


Solution 1:[1]

Query

  • split the genre string on "|"
  • unwind so each document 1 genre
  • group and count the genres

*i think you should also update the collection and make the genre a normal array, having strings with "|" doesn't seem good schema.

Playmongo

aggregate(
[{"$set": {"genres": {"$split": ["$genres", "|"]}}},
 {"$unwind": "$genres"},
 {"$group": {"_id": "$genres", "count": {"$sum": 1}}}])

Sources

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Source: Stack Overflow

Solution Source
Solution 1 Takis

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