MongoDBQueriesManager

Convert query parameters from API urls to MongoDB queries !

This project was inspired by api-query-params (JS Library).

Features:

• Powerful: Supports most of MongoDB operators ($in, $regexp, ...) and features (nested objects, type casting, projection, range filter...)
• Agnostic: Works with any web frameworks (Flask, Sanic, AIOHTTP, Django ...) and/or MongoDB libraries (pymongo, motor, ...)
• Simple: ~500 LOC, Python typing
• Tested: 100% code coverage

Installation:

⚠️ In version 1.0.0 dateparser is an extra dependencies

pip install mongo-queries-manager
pip install mongo-queries-manager['dateparser']

# OR

pipenv install mongo-queries-manager
pipenv install mongo-queries-manager['dateparser']

# OR

poetry add mongo-queries-manager
poetry add mongo-queries-manager['dateparser']

Usages:

Api

mqm(string_query: str, blacklist: Optional[List[str]] = None, casters: Optional[Dict[str, Callable]] = None, populate: bool = False) -> Dict[str, Any]:

Description

Converts string_query into a MongoDB query dict.

Arguments

• string_query: query string of the requested API URL (ie, frist_name=John&limit=10), Works with url encoded. [required]
• casters: Custom caster dict, used to define custom type (ie, casters={'string': str} / price=string(5.5) -> {'price': '5'}) [optional]
• blacklist: Custom blacklist word, used to ignore specific value from query (ie, blacklist=[where] / company=id,where=43.60,1.44, -> {'company': 'id'}) [optional]
• populate: A boolean value, used to activate the population logic (add a population field into returned dict)

Returns

The resulting dictionary contains the following properties:

• filter: Contains the query criteria.
• projection: Contains the query projection
• sort: Contains the sort criteria (cursor modifiers).
• skip: Contains the skip criteria (cursor modifiers).
• limit: Contains the limit criteria (cursor modifiers).
• population: Contains the population criteria. (Only when populate arg is true. To use this population list, a manual implementation is required)

Exception

In case of error the following exception was raised:

• MongoDBQueriesManagerBaseError: Base MongoDBQueriesManager errors.
• SkipError: Raised when skip is negative / bad value.
• LimitError: Raised when limit is negative / bad value.
• ListOperatorError: Raised list operator was not possible.
• FilterError: Raised when parse filter method fail to find a valid match.
• TextOperatorError: Raised when parse text operator contain an empty string.
• CustomCasterFail: Raised when a custom cast fail.
• ProjectionError: Raised when projection json is invalid.
• LogicalPopulationError: Raised when method fail to find logical population item.
• LogicalSubPopulationError: Raised when method fail to find logical sub population item.

Examples:

Simple demo

from mongo_queries_manager import mqm

mongodb_query = mqm(string_query="status=sent&price>=5.6&active=true&timestamp>"
                                 "2016-01-01&author.firstName=/john/i&limit=100&skip=50&sort=-timestamp&fields=-_id,-created_at")

# {
#   'filter':
#       {
#           'status': 'sent',
#           'price': {'$gte': 5.6},
#           'active': True,
#           'timestamp': {'$gt': datetime.datetime(2016, 1, 1, 0, 0)},
#           'author.firstName': re.compile('/john/i')
#       },
#   'projection': {'_id': 0, 'created_at': 0},
#   'sort': [('timestamp', -1)],
#   'skip': 50,
#   'limit': 100
# }

Examples with PyMongo

from typing import Dict, Any

from pymongo import MongoClient
from pymongo.collection import Collection
from pymongo.database import Database

from mongo_queries_manager import mqm

client: MongoClient = MongoClient('localhost', 27017)
db: Database = client['test-database']
collection: Collection = db['test-collection']

mongodb_query: Dict[str, Any] = mqm(string_query="status=sent&toto=true&timestamp>2016-01-01&"
                                                 "author.firstName=/john/i&limit=100&skip=50&sort=-timestamp")

result = collection.find(**mongodb_query)

Supported features

Filter operators:

MongoDB	URI	Example	Result
$eq	key=val	type=public	{'filter': {'type': 'public'}}
$gt	key>val	count>5	{'filter': {'count': {'$gt': 5}}}
$gte	key>=val	rating>=9.5	{'filter': {'rating': {'$gte': 9.5}}}
$lt	key<val	createdAt<2016-01-01	{'filter': {'createdAt': {'$lt': datetime.datetime(2016, 1, 1, 0, 0)}}}
$lte	key<=val	score<=-5	{'filter': {'score': {'$lte': -5}}}
$ne	key!=val	status!=success	{'filter': {'status': {'$ne': 'success'}}}
$in	key=val1,val2	country=GB,US	{'filter': {'country': {'$in': ['GB', 'US']}}}
$nin	key!=val1,val2	lang!=fr,en	{'filter': {'lang': {'$nin': ['fr', 'en']}}}
$exists	key	phone	{'filter': {'phone': {'$exists': True}}}
$exists	!key	!email	{'filter': {'email': {'$exists': False}}}
$regex	key=/value/<opts>	email=/@gmail\.com$/i	{'filter': {'email': re.compile('/@gmail.com$/i')}}
$regex	key!=/value/<opts>	phone!=/^06/	{'filter': {'phone': { '$not': re.compile('/^06/')}}}
$text	$text=val	$text=toto -java	{'filter': {'$text': { '$search': 'toto -java'}}}
$text	$text=val	$text="toto"	{'filter': {'$text': { '$search': '"toto"'}}}

Skip / Limit operators:

• Default operator keys are skip and limit.
• Used to limit the number of records returned by the query (pagination, result limitation, ...).
• Support empty value (ie, ...&skip=&... / ...&limit=&... ).

from typing import Dict, Any

from mongo_queries_manager import mqm

mongodb_query: Dict[str, Any] = mqm(string_query="skip=50&limit=50")
# {
#   'filter': {},
#   'sort': None,
#   'projection': None,
#   'skip': 50,
#   'limit': 50
# }

mongodb_query: Dict[str, Any] = mqm(string_query="skip=&limit=")
# {
#   'filter': {},
#   'sort': None,
#   'projection': None,
#   'skip': 0,
#   'limit': 0
# }

Sort operator:

• Used to sort returned records.
• Default operator key is sort.
• Support empty value (ie, ...&sort=&...).
• Sort accepts a comma-separated list of fields.
• Default behavior is to sort in ascending order.
• Use - prefixes to sort in descending order, use + prefixes to sort in ascending order.

from typing import Dict, Any

from mongo_queries_manager import mqm

mongodb_query: Dict[str, Any] = mqm(string_query="sort=created_at,-_id,+price")
#{
#   'filter': {},
#   'sort': [('created_at', 1), ('_id', -1), ('price', 1)],
#   'projection': None,
#   'skip': 0,
#   'limit': 0
#}

Projection operator:

• Useful to limit fields to return in each records.
• It accepts a comma-separated list of fields. Default behavior is to specify fields to return. Use - prefixes to return all fields except some specific fields.
• Due to a MongoDB limitation, you cannot combine inclusion and exclusion semantics in a single projection with the exception of the _id field.
• It also accepts JSON string to use more powerful projection operators ($, $elemMatch or $slice)

from typing import Dict, Any

from mongo_queries_manager import mqm

mongodb_query: Dict[str, Any] = mqm(string_query="fields=-_id,-price")
#{
#   'filter': {},
#   'sort': None,
#   'projection': {'_id': 0, 'price': 0},
#   'skip': 0,
#   'limit': 0
#}


mongodb_query: Dict[str, Any] = mqm(string_query="fields=_id,price")

#{
#   'filter': {},
#   'sort': None,
#   'projection': {'_id': 1, 'price': 1},
#   'skip': 0,
#   'limit': 0
#}


mongodb_query: Dict[str, Any] = mqm(
    string_query='fields={"games": {"$elemMatch":{"score": {"$gt": 5}}}},joined,lastLogin')

#{
#   'filter': {},
#   'sort': None,
#   'projection': {'games': {'$elemMatch': {'score': {'$gt': 5}}}, 'joined': 1, 'lastLogin': 1}},
#   'skip': 0,
#   'limit': 0
#}

Range filter:

• Useful to filter fields to return in each records by range.
• No error was handle by this library for range filter

from typing import Dict, Any

from mongo_queries_manager import mqm

query_result: Dict[str, Any] = mqm(string_query="price>5&price<5")

# {
# 'filter':
# {
#   'price': {'$gt': 5.0, '$lt': 5.0},
#   },
#   'sort': None,
#   'projection': None,
#   'skip': 0,
#   'limit': 0
# }

Custom caster:

• Used to define custom type
• Optional parameter

from typing import Dict, Any, List

from mongo_queries_manager import mqm


def parse_custom_list(custom_list: str) -> List[str]:
    return custom_list.split(';')


query_result: Dict[str, Any] = mqm(string_query="price=string(5)&name=John&in_stock=custom_list(1;2;3;4)&"
                                                "in_stock_string=custom_list(string(1);string(2);string(3);string(4))",
                                   casters={'string': str, 'custom_list': parse_custom_list})

#{
# 'filter':
# {
#   'price': '5',
#   'name': 'John',
#   'in_stock': {'$in': [1, 2, 3, 4]},
#   'in_stock_string': {'$in': ['1', '2', '3', '4']}
#   },
#   'sort': None,
#   'projection': None,
#   'skip': 0,
#   'limit': 0
#}

Contribution

Install all development dependencies

# Initialize a new virtual environment
poetry shell

# Install dev dependencies
poetry install --with format,lint,type,tools,tests -E dateparser

# Run tests
nox

# Pre commit (format / lint / type before commit)
pre-commit install
pre-commit run --all-files