python - Why using integer as setting _id with pymongo doesn't work? -

this question has answer here:

• pymongo saving embedded objectids, invaliddocumenterror 1 answer

i've tried larger data set in python , had issues, created small test set, in python pymongo:

from pymongo import mongoclient testcoll = mongoclient().tdb.tcoll data = {'foo': 'bar', 'baz': {1: {'a': 'b'}}, '_id': 'ab123456789'} testcoll.insert(data) 

this returns

bson.errors.invaliddocument: documents must have string keys, key 1 

replacing 1 in dictionary in baz 2 changes error key 2 accordingly

why this? missing ids in mongo?

i've submitted edit title of post considering misleading problem having. not trying update _id field indicated rather python dictionary definition incompatible bson spec.

in line:

data = {'foo': 'bar', 'baz': {1: {'a': 'b'}}, '_id': 'ab123456789'} 

you have numeric (integer) key value for, in mongo terms, document. deriving json, within bson spec not valid keys must strings required in specification.

bson.errors.invaliddocument: documents must have string keys, key 1 

you need keep of keys in python code strings in order compliant.

data = {'foo': 'bar', 'baz': {'1': {'a': 'b'}}, '_id': 'ab123456789'} 

changing representation of key string fixes problem.

as note, consider document structure there several disadvantages of using type of notation (if want access numerical index ) in mongodb documents collection on using array.