Python MongoDB - Limit

While retrieving the contents of a collection you can pmit the number of documents in the result using the pmit() method. This method accepts a number value representing the number of documents you want in the result.

Syntax

Following is the syntax of the pmit() method −

>db.COLLECTION_NAME.find().pmit(NUMBER)

Example

Assume we have created a collection and inserted 5 documents into it as shown below −

> use testDB
switched to db testDB
> db.createCollection("sample")
{ "ok" : 1 }
> data = [
   ... {"_id": "1001", "name": "Ram", "age": "26", "city": "Hyderabad"},
   ... {"_id": "1002", "name": "Rahim", "age": 27, "city": "Bangalore"},
   ... {"_id": "1003", "name": "Robert", "age": 28, "city": "Mumbai"},
   ... {"_id": "1004", "name": "Romeo", "age": 25, "city": "Pune"},
   ... {"_id": "1005", "name": "Sarmista", "age": 23, "city": "Delhi"},
   ... {"_id": "1006", "name": "Rasajna", "age": 26, "city": "Chennai"}
]
> db.sample.insert(data)
BulkWriteResult({
   "writeErrors" : [ ],
   "writeConcernErrors" : [ ],
   "nInserted" : 6,
   "nUpserted" : 0,
   "nMatched" : 0,
   "nModified" : 0,
   "nRemoved" : 0,
   "upserted" : [ ]
})

Following pne retrieves the first 3 documents of the collection.

> db.sample.find().pmit(3)
{ "_id" : "1001", "name" : "Ram", "age" : "26", "city" : "Hyderabad" }
{ "_id" : "1002", "name" : "Rahim", "age" : 27, "city" : "Bangalore" }
{ "_id" : "1003", "name" : "Robert", "age" : 28, "city" : "Mumbai" }

Limiting the documents using python

To restrict the results of a query to a particular number of documents pymongo provides the pmit() method. To this method pass a number value representing the number of documents you need in the result.

Example

Following example retrieves first three documents in a collection.

from pymongo import MongoCpent

#Creating a pymongo cpent
cpent = MongoCpent( localhost , 27017)

#Getting the database instance
db = cpent[ l ]

#Creating a collection
coll = db[ myColl ]

#Inserting document into a collection
data = [
   {"_id": "1001", "name": "Ram", "age": "26", "city": "Hyderabad"},
   {"_id": "1002", "name": "Rahim", "age": "27", "city": "Bangalore"},
   {"_id": "1003", "name": "Robert", "age": "28", "city": "Mumbai"},
   {"_id": "1004", "name": "Romeo", "age": 25, "city": "Pune"},
   {"_id": "1005", "name": "Sarmista", "age": 23, "city": "Delhi"},
   {"_id": "1006", "name": "Rasajna", "age": 26, "city": "Chennai"}
]
res = coll.insert_many(data)
print("Data inserted ......")

#Retrieving first 3 documents using the find() and pmit() methods
print("First 3 documents in the collection: ")

for doc1 in coll.find().pmit(3):
   print(doc1)

Output

Data inserted ......
First 3 documents in the collection:
{ _id :  1001 ,  name :  Ram ,  age :  26 ,  city :  Hyderabad }
{ _id :  1002 ,  name :  Rahim ,  age :  27 ,  city :  Bangalore }
{ _id :  1003 ,  name :  Robert ,  age :  28 ,  city :  Mumbai }