Geospatial Indexing Example

This example shows how to create and use a GEO2D index in PyMongo.

See also

See general MongoDB documentation

geo

Creating a Geospatial Index

Creating a geospatial index in pymongo is easy:

>>> from pymongo import MongoClient, GEO2D
>>> db = MongoClient().geo_example
>>> db.places.create_index([("loc", GEO2D)])
u'loc_2d'

Inserting Places

Locations in MongoDB are represented using either embedded documents or lists where the first two elements are coordinates. Here, we’ll insert a couple of example locations:

>>> result = db.places.insert_many([{"loc": [2, 5]},
...                                 {"loc": [30, 5]},
...                                 {"loc": [1, 2]},
...                                 {"loc": [4, 4]}])
>>> result.inserted_ids
[ObjectId('...'), ObjectId('...'), ObjectId('...'), ObjectId('...')]

Querying

Using the geospatial index we can find documents near another point:

>>> for doc in db.places.find({"loc": {"$near": [3, 6]}}).limit(3):
...   repr(doc)
...
"{u'loc': [2, 5], u'_id': ObjectId('...')}"
"{u'loc': [4, 4], u'_id': ObjectId('...')}"
"{u'loc': [1, 2], u'_id': ObjectId('...')}"

The $maxDistance operator requires the use of SON:

>>> from bson.son import SON
>>> for doc in db.places.find({"loc": SON([("$near", [3, 6]), ("$maxDistance", 100)])}).limit(3):
...   repr(doc)
...
"{u'loc': [2, 5], u'_id': ObjectId('...')}"
"{u'loc': [4, 4], u'_id': ObjectId('...')}"
"{u'loc': [1, 2], u'_id': ObjectId('...')}"

It’s also possible to query for all items within a given rectangle (specified by lower-left and upper-right coordinates):

>>> for doc in db.places.find({"loc": {"$within": {"$box": [[2, 2], [5, 6]]}}}):
...   repr(doc)
...
"{u'loc': [2, 5], u'_id': ObjectId('...')}"
"{u'loc': [4, 4], u'_id': ObjectId('...')}"

Or circle (specified by center point and radius):

>>> for doc in db.places.find({"loc": {"$within": {"$center": [[0, 0], 6]}}}):
...   repr(doc)
...
"{u'loc': [1, 2], u'_id': ObjectId('...')}"
"{u'loc': [2, 5], u'_id': ObjectId('...')}"
"{u'loc': [4, 4], u'_id': ObjectId('...')}"

geoNear queries are also supported using SON:

>>> from bson.son import SON
>>> db.command(SON([('geoNear', 'places'), ('near', [1, 2])]))
{u'ok': 1.0, u'stats': ...}