PyMongo iterate embedded objects

Posted under » MongoDB on 29 August 2024

To count embedded objects use the len method. After you get the len then you can iterate.

myquery =  { "cid" : 2118 }
for x in mthlog.find(myquery):
    howmany = len(x["band-06"])
    print(howmany)
    for i in range(howmany):
        pprint.pprint(x["band-06"][i]['band'])

len will only work if the list do exist. Otherwise there will be a 'key' error. To be safe, it is best that you make sure, there is something to len with by

myquery =  { "cid" : 2118, "band-06" : {"$ne" : None} }
for x in mthlog.find(myquery):
    howmany = len(x["band-06"])
    print(howmany)

Another issue is that "band-06" must be consistent. You cannot have list and then integer. You can't len an integer.