CODEWITHSUNDEEP
pythonmongodbaggregation-frameworkpymongo
AlyData
AlyData

Reputation: 11

Python MongoDB Aggregate error

This code gives me an error:

TypeError: 'CommandCursor' object has no attribute 'getitem'

However when my friend runs the same code on her computer, she doesn't get an error. I'm using an Intel Pentium CPU on Windows. I have MongoDB running (version 3.4), Python 2.7.13 :: Anaconda 4.3.1 (64-bit). 

import json
import pymongo 
from bson import json_util
import re

FROM = "[email protected]"

client = pymongo.MongoClient()
db = client.enron    
mbox = db.mbox

//Get the recipient lists for each message

recipients_per_message = db.mbox.aggregate([
{"$match" : {"From" : re.compile(r".*{0}.*".format(FROM), re.IGNORECASE)}}, 
{"$project" : {"From" : 1, "To" : 1} }, 
{"$group" : {"_id" : "$From", "recipients" : {"$addToSet" : "$To" } } }                    
])['result'][0]['recipients']

//The exact Error was:
TypeError Traceback (most recent call last) 
19 {"$project" : {"From" : 1, "To" : 1} },   
20 {"$group" : {"_id" : "$From", "recipients" : {"$addToSet":"$To" }}}  
---> 21 ])['result'][0]['recipients'] 
TypeError: 'CommandCursor' object has no attribute 'getitem'

Upvotes: 1

Views: 2826

Answers (1)

A. Jesse Jiryu Davis
A. Jesse Jiryu Davis

Reputation: 24007

Your friend must be running an old version of both MongoDB and PyMongo. Since PyMongo 3.0, running "aggregate" with PyMongo returns a cursor that you must iterate for results. Try this:

results = list(db.mbox.aggregate([
    {"$match" : {"From" : re.compile(r".*{0}.*".format(FROM), re.IGNORECASE)}}, 
    {"$project" : {"From" : 1, "To" : 1} }, 
    {"$group" : {"_id" : "$From", "recipients" : {"$addToSet" : "$To" } } }                    
]))
recipients_per_message = results['result'][0]['recipients']

Upvotes: 1

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