How to limit mongo query in python

Mulagala picture Mulagala · Apr 13, 2015 · Viewed 31.8k times · Source

I am trying to retrieve data from mongodb with python. My db contains lots of data. So I want to limit the data while retrieving. I tried

import datetime
from pymongo import Connection
connection = Connection('localhost',27017)
db = connection['MyWork']


db_data = db.myusers.find().limit(2)
#db_data = db.myusers.find()[0:2]
print db_data
print db_data.count()
print db_data[0]
print db_data[1]
print db_data[2]

But I am getting more than two documents when I tried above. I am using pymongo driver. How to limit the values

<pymongo.cursor.Cursor object at 0x000000000267D518>
3
{u'age': 24.0, u'_id': ObjectId('552b6e90aad3e2d909d5fb28'), u'place': u'Ravipadu', u'name': u'Shiva'}
{u'age': 28.0, u'_id': ObjectId('552b6eabaad3e2d909d5fb29'), u'place': u'Rajahmundry', u'name': u'Anil'}
{u'age': 30.0, u'_id': ObjectId('552b6ec1aad3e2d909d5fb2a'), u'place': u'Manchili', u'name': u'Kishore'}

Answer

taskinoor picture taskinoor · Apr 13, 2015

As specified in this question, indexed access will ignore the limit. And count() does not obey limit or skip by default as explained the manual. You can pass with_limit_and_skip=True to make count() work with limit.

print db_data.count(with_limit_and_skip=True)

Or you can iterate the cursor to see limit in effect.

for data in db.myusers.find().limit(2):
    print data