How to create dynamic PyMongo query handling ISODate?

Question

I am developing a Flask REST API which will have three query parameters (HomeDevice, Key, UpdateDate), all passed as string. Now, I have to PyMongo query on Mongodb using these three inputs as filters.

typeof db.getCollection('collection_name').findOne().updatedate
>> Object

import json
from pymongo import MongoClient
import pandas as pd

client = MongoClient(<ServerAddress>,27017)
db = client.db_name
col = db.collection_name

updatedate="2020-01-13 06:43:47.500Z"
print(updatedate)

var = '{ "$and" : [{"homeDevice" : "Loader"} , {"key" : "OP2561NX" },{"updatedate" : ISODate("2020-01-13 06:43:47.500Z")}]}'
data = json.loads(var)
docs = pd.DataFrame(list(col.find(data)))
print(docs) 

ISODate(updateDate) is causing JSONDecodeError, and after removing ISODate casting, query fetches empty frame.

JSONDecodeError                           Traceback (most recent call last)
<ipython-input-12-95360c676df4> in <module>
     11 
     12 var = '{ "$and" : [{"homeDevice" : "Loader"} , {"keyed" : "OP2561NX" },{"updatedate" : ISODate("2020-01-13 06:43:47.500Z")}]}'
---> 13 data = json.loads(var)
     14 docs = pd.DataFrame(list(col.find(data)))
     15 print(docs)

E:\Analytics\Installations\Anaconda3\lib\json\__init__.py in loads(s, encoding, cls, object_hook, parse_float, parse_int, parse_constant, object_pairs_hook, **kw)
    346             parse_int is None and parse_float is None and
    347             parse_constant is None and object_pairs_hook is None and not kw):
--> 348         return _default_decoder.decode(s)
    349     if cls is None:
    350         cls = JSONDecoder

E:\Analytics\Installations\Anaconda3\lib\json\decoder.py in decode(self, s, _w)
    335 
    336         """
--> 337         obj, end = self.raw_decode(s, idx=_w(s, 0).end())
    338         end = _w(s, end).end()
    339         if end != len(s):

E:\Analytics\Installations\Anaconda3\lib\json\decoder.py in raw_decode(self, s, idx)
    353             obj, end = self.scan_once(s, idx)
    354         except StopIteration as err:
--> 355             raise JSONDecodeError("Expecting value", s, err.value) from None
    356         return obj, end

JSONDecodeError: Expecting value: line 1 column 81 (char 80)

Running this query directly in monogodb (Robo3T) returns data. I need a way to create query dynamically and apply ISODate on updatedate key.

How to create dynamic PyMongo query to handle ISODate?

Answer 1

Construct var like a dictionary:

var = { "$and" : [{"homeDevice" : "Loader"} , {"key" : "OP2561NX" },{"updatedate" : ISO("2020-01-13 06:43:47.500Z")}]}

and use it like:

col.find(var)

You don't need to convert it to string/JSON.

Try the above and let me know.