PyMongo-使用for打印结果，但不显示

Question

recently we've been learning Mongo and Python at University, however, in the latest assignment we were given, we're required to use PyMongo to use a pre-existent database of restaurants and perform various basic tasks.

Due to a surgery, I couldn't assist to the lectures given, so I'm still a bit confused onto how to do certain things with PyMongo.

One part of the task is write some querys to do stuff like "searching restaurants with latitudes lower than -90" and similar tasks.

My code looks a bit like this:

conn = pymongo.MongoClient()
restDB = conn.restaurantes
doc = restDB.datos


prim = doc.find({"address.coord.0":{"$lt":-95.754168}}, {"name":True})
for resultado in prim:
    print resultado

#print prim

Whenever I do this, no results are displayed and there are no errors as well, so that's what confuses me. Also trying to print "prim" gives me some .cursor message.

Answer 1

The basic template for querying a collection and iterating through the result with pymongo is:

from pymongo import MongoClient

with MongoClient() as client:
    db = client.get_database("my_db_name")
    coll = db.get_collection("my_collection_name")
    result_cursor = coll.find({"some_field":{"$lt":100}}, {"some_field":1})
    for doc in result_cursor:
        print doc

>>
{u'some_field': 3, u'_id': ObjectId('578d52a93ea71afa979e5737')}
...