Syntax

collection.create_index([(field, direction)], **options)

Parameters:

• field: Field to index (e.g., "name")
• direction: pymongo.ASCENDING or pymongo.DESCENDING
• options:Additional index options like unique=True, name="customIndex" etc.

Here is our sample data.

frompymongoimportMongoClient,ASCENDINGc=MongoClient("mongodb://localhost:27017/")db=c["indexDB"]col=db["users"]data=[{"name":"Alice","email":"alice@example.com"},{"name":"Bob","email":"bob@example.com"},{"name":"Charlie","email":"charlie@example.com"}]col.delete_many({})col.insert_many(data)print("Sample data inserted.")

Output

Sample data inserted

Explanation:

• Connects to the local MongoDB server and selects theindexDBdatabase and users collection.
• Clears existing documents in the collection usingdelete_many({}).
• Inserts three sample user records into the collection usinginsert_many().

Examples

Example 1: Create index on a field

frompymongoimportMongoClient,ASCENDINGc=MongoClient("mongodb://localhost:27017/")db=c["indexDB"]col=db["users"]idx_name=col.create_index([("name",ASCENDING)])print(idx_name)

Output

Explanation: Creates an ascending index on the name field to speed up queries using name.

Example 2: List all index

frompymongoimportMongoClient,ASCENDINGc=MongoClient("mongodb://localhost:27017/")db=c["indexDB"]col=db["users"]foridxincol.list_indexes():print(idx)

Output

Explanation: Displays all indexes on the users collection. The default _id_ index and the createdname_1 index will be shown.

Example 3: Drop an index

frompymongoimportMongoClient,ASCENDINGc=MongoClient("mongodb://localhost:27017/")db=c["indexDB"]col=db["users"]col.drop_index("name_1")

Output

Index dropped

Explanation: Drops the index named"name_1". You must pass the exact index name created earlier.

Example 4: Create index on a new field (default ascending)

frompymongoimportMongoClient,ASCENDINGc=MongoClient("mongodb://localhost:27017/")db=c["indexDB"]col=db["users"]res=col.create_index("index_created")print(res)

Output

index_created_1

Explanation: Creates an ascending index (default) on a new fieldindex_created.

Example 5: Create compound index

frompymongoimportMongoClient,ASCENDINGc=MongoClient("mongodb://localhost:27017/")db=c["indexDB"]col=db["users"]res=col.create_index([("ascending_index",1),("second_descending_index",DESCENDING)])print(res)

Output

Explanation: ascending_index is indexed in ascending order,second_descending_indexin descending order. This index improves performance for queries and sorts using both fields together.