Get all documents of a collection using Pymongo

Question

I want to write a function to return all the documents contained in mycollection in mongodb

from pymongo import MongoClient

if __name__ == '__main__':
    client = MongoClient("localhost", 27017, maxPoolSize=50)
    db=client.mydatabase
    collection=db['mycollection']
    cursor = collection.find({})
    for document in cursor:
        print(document)

However, the function returns: Process finished with exit code 0

have you tried without braces in the find method? try cursor = db.mycollection.find() — YOBA, Jun 21 '16 at 10:19
Ok, how are you executing this script? (Also please adjust the indentation) — YOBA, Jun 21 '16 at 10:43
Ok this is a pycharm specific usage problem because your code is fine. Also check that you run directly your script as the main one, since you have \__name\__ == '\__main\__' in your code, try using a console to check the connectivity with the database. — YOBA, Jun 21 '16 at 10:52
I checked the connectivity and It's OK. SO, I could print all collection of my database — MAYA, Jun 21 '16 at 10:55
how I can do this? It returns the same output : Process finished with exit code 0 — MAYA, Jun 21 '16 at 11:00
I tried the same code as OP posted in my Linux machine with different db and collection. It worked well for me. — Girish Gupta, Jun 21 '16 at 11:23

score 103 · Answer 1 · edited Jan 02 '18 at 13:52

103

Here is the sample code which works fine when you run from command prompt.

from pymongo import MongoClient

if __name__ == '__main__':
    client = MongoClient("localhost", 27017, maxPoolSize=50)
    db = client.localhost
    collection = db['chain']
    cursor = collection.find({})
    for document in cursor:
          print(document)

Please check the collection name.

edited Jan 02 '18 at 13:52

razieh babaee

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answered Jun 21 '16 at 11:00

notionquest

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It the same what I did – MAYA Jun 21 '16 at 11:14
I have pasted the above code to confirm that there is no problem in the code. It is something to do with the local environment. Also, I mentioned that it works fine from command prompt. – notionquest Jun 21 '16 at 11:20
I understand. Finally, it works The problem was in the collection name Thank you – MAYA Jun 21 '16 at 11:30
Why are `json` and `pymongo` imported for this [mcve]? – boardrider Sep 23 '17 at 09:52
This seem slow. Is there not a more performant way to download all the documents? – Barry G Mar 23 '23 at 16:17

score 61 · Answer 2 · edited Oct 22 '19 at 13:39

61

pymongo creates a cursor. Hence you'll get the object 'under' the cursor. To get all objects in general try:

list(db.collection.find({}))

This will force the cursor to iterate over each object and put it in a list()

Have fun...

edited Oct 22 '19 at 13:39

geisterfurz007

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answered Apr 15 '19 at 09:50

Robert Nagtegaal

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score 12 · Answer 3 · edited Aug 14 '18 at 06:10

12

I think this will work fine in your program.

cursor = db.mycollection # choosing the collection you need

for document in cursor.find():
    print (document)

edited Aug 14 '18 at 06:10

Gautam Savaliya

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answered Aug 14 '18 at 04:27

Isuru Maldeniya

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Here `cursor = db.mycollection` do not name variable as cursor it would ideal to name as `collection`, Just not to confuse as `cursor.find():` should be `collection.find():` which returns a `cursor` that can be iterated over to get the values out. – whoami - fakeFaceTrueSoul May 11 '20 at 15:31

score 0 · Answer 4 · answered Feb 24 '22 at 08:00

it works fine for me,try checking the exact database name and collection name. and try changing from db=client.mydatabase to db=client['mydatabase'] .

If your database name is such that using attribute style access won’t work (like test-database), you can use dictionary style access instead. source !

Get all documents of a collection using Pymongo

4 Answers4