How to compare dates from MongoDB object in python?

Question

I am trying to work out the difference in years between a MongoDB object and Today's date. The MongoDB object looks like this:

Key: Value

club_joined: 2021-08-10T00:00:00.000+00:00

I have the python code (that works):

loyal_players = []

for player in players.find():
    # get time players have been at club
    current_date = datetime.today()
    joined_club = player['club_joined']

    time_at_club = relativedelta(current_date, joined_club)
    time_at_club_years = time_at_club.years

    # check if they are over 10 years
    if time_at_club_years >= 10:
        loyal_players.append(player['short_name'])

But what I want is a Mongo query that can add into the .find() line:

for player in players.find():

I know the logic behind it is:

for player in players.find(
    where (
        (todayDate - player['club_joined']) > 10
    ):

But how do I write this as a MongoDB query in python?

MongoDb Type:

Double checking: is club_joined an ISO8601 string? Not a real mongodb datetime? — Buzz Moschetti
– Buzz Moschetti, Commented Dec 14, 2021 at 18:33
@BuzzMoschetti no, it is a Date, I will add a screenshot to my question to show — RC07JNR
– RC07JNR, Commented Dec 14, 2021 at 18:43
@RC07JNR Would you be able to just covert to timestamp milliseconds and take the difference, and calculate the days/months/years? Or would that be too consuming for your app (after querying the data) — Jacob
– Jacob, Commented Dec 14, 2021 at 18:49
@Jacob If that can be added into the .find() of the MongoDD line that would probably work but I'm not sure how to do that! — RC07JNR
– RC07JNR, Commented Dec 14, 2021 at 18:50
@RC07JNR stackoverflow.com/questions/35852223/query-mongo-on-timestamp - Would this help? — Jacob
– Jacob, Commented Dec 14, 2021 at 18:54

Buzz Moschetti · Accepted Answer · 2021-12-14 20:55:10Z

2

The $subtract function will take 2 dates and return the diff in millis so this works:

    from pymongo import MongoClient
    import datetime

    now = datetime.datetime.now()

    TARG = 86400 * 1000 * 365 * 10 # secs in day X millis X 365 days X 10 yrs                            

    cursor = db.foo.aggregate([
        {"$match": {"$expr": {"$gt": [ {"$subtract": [now,"$club_joined"]}, TARG ] } }}
    ])
    for doc in cursor:
        print(doc)

edited Dec 14, 2021 at 20:55

answered Dec 14, 2021 at 19:02

Buzz Moschetti

7,6433 gold badges27 silver badges41 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

RC07JNR Over a year ago

I think this is along the right line! That gives me the following error tho: Unresolved attribute reference 'datetime' for class 'datetime'. My import = from datetime import datetime and the line is exactly what you have, any ideas?

Buzz Moschetti Over a year ago

I added the 2 imports to my answer as they appear in my working example. Don't be shy to accept the answer and upvote. ;-)

RC07JNR Over a year ago

Aww amazing! Thank you so much

Belly Buster · Accepted Answer · 2021-12-14 23:54:48Z

0

Using relativedelta seems simpler:

import datetime
from dateutil.relativedelta import relativedelta

dt = datetime.datetime.now() - relativedelta(years=10)

cursor = db.foo.find({'club_joined': {'$lt': dt}})

for doc in cursor:
    print(doc)

answered Dec 14, 2021 at 23:54

Belly Buster

8,9142 gold badges12 silver badges25 bronze badges

1 Comment

Buzz Moschetti Over a year ago

It does. I am a\lways trying to demo the agg functions.

Tanjin Alam · Accepted Answer · 2024-01-26 05:18:26Z

0

Following code with logic of expire time of 3 mintues of previously inserted data works fine.

today = datetime.today()
time_threshold = today - timedelta(minutes=3)


data = mongo_client[db_name][f'{instrument_name}'].find_one({
    "$or": [
        {
            "$and": [
                {"updated_at": {"$lt": time_threshold}},
                {"updated_at": {"$exists": True}},
            ]
        },
        {
            "$and": [
                {"generated": "Error"},
                {"updated_at": {"$exists": False}},
            ]
        },
    ],
})

answered Jan 26, 2024 at 5:18

Tanjin Alam

2,6541 gold badge18 silver badges22 bronze badges

Collectives™ on Stack Overflow

How to compare dates from MongoDB object in python?

3 Answers 3

3 Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related