Querying for null field using pymongo

Question

I would like to query for a null field in mongo using python, however it struggles to deal with the words null or false. it either gives me the error that they are undefined in python or it searches for the string null and false in mongo, neither of which I want to happen.

collection = pymongo.MongoClient('mongodb://localhost:27017/')['historical'].highjump
1) data = pd.DataFrame(list(collection.find({"min":"null"})))
2) data = pd.DataFrame(list(collection.find({"min":null})))
3) data = pd.DataFrame(list(collection.find({"min":{"$exists":"false"}})))
4) data = pd.DataFrame(list(collection.find({"min":{"$exists":false}})))

1&3) error because searching for the string null/false in the field instead of searching for when the field doesn't exist.
2&4) error because null/false is not defined in python.

Any help would be greatly appreciated, I can run queries 2 & 4 within mongo and return the correct documents, but I need to run it from the python shell.

WGP · Accepted Answer · 2017-04-20 09:42:13Z

8

Replacing false with False in method 4, or null with None in 2 works.

answered Apr 20, 2017 at 9:42

WGP

7482 gold badges7 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Querying for null field using pymongo

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related