montydb 2.1.1

MongoDB's unofficial Python implementation.

Monty, Mongo tinified. MongoDB implemented in Python !

Inspired by TinyDB and it's extension TinyMongo.

---

MontyDB is:

• A tiny version of MongoDB, against to MongoDB 4.0.11
• Written in pure Python, testing on Python 2.7, 3.6, 3.7, 3.8, PyPy*
• Literally serverless.
• Similar to mongomock, but a bit more than that.

All those implemented functions and operators, should behaved just like you were working with MongoDB. Even raising error for same cause.

Install

pip install montydb

Optinal Requirements

• lmdb (for LMDB storage lightning)

• pymongo (for bson)

  bson is opt-out by default even it's installed, set env var MONTY_ENABLE_BSON=1 to enable it.

Example Code

>>> from montydb import MontyClient
>>> col = MontyClient(":memory:").db.test
>>> col.insert_many([{"stock": "A", "qty": 6}, {"stock": "A", "qty": 2}])

>>> cur = col.find({"stock": "A", "qty": {"$gt": 4}})
>>> next(cur)
{'_id': ObjectId('5ad34e537e8dd45d9c61a456'), 'stock': 'A', 'qty': 6}

Development

• You may visit Projects' TODO to see what's going on.
• You may visit This Issue to see what's been implemented and what's not.

Storage Engine Configurations

The configuration process only required on repository creation or modification.

Currently, one repository can only assign one storage engine.

• Memory

Memory storage does not need nor have any configuration, nothing saved to disk.

>>> from montydb import MontyClient
>>> client = MontyClient(":memory:")

• FlatFile

FlatFile is the default on-disk storage engine.

>>> from montydb import MontyClient
>>> client = MontyClient("/db/repo")

FlatFile config:

[flatfile]
cache_modified: 0  # how many document CRUD cached before flush to disk.

• LMDB (Lightning Memory-Mapped Database)

LMDB is NOT the default on-disk storage, need configuration first before get client.

Newly implemented.

>>> from montydb import set_storage, MontyClient
>>> set_storage("/db/repo", storage="lightning")
>>> client = MontyClient("/db/repo")

LMDB config:

[lightning]
map_size: 10485760  # Maximum size database may grow to.

• SQLite

SQLite is NOT the default on-disk storage, need configuration first before get client.

Pre-existing sqlite storage file which saved by montydb<=1.3.0 is not read/writeable after montydb==2.0.0.

>>> from montydb import set_storage, MontyClient
>>> set_storage("/db/repo", storage="sqlite")
>>> client = MontyClient("/db/repo")

SQLite config:

[sqlite]
journal_mode: WAL

SQLite write concern:

>>> client = MontyClient("/db/repo",
>>>                      synchronous=1,
>>>                      automatic_index=False,
>>>                      busy_timeout=5000)

MontyDB URI

You could prefix the repository path with montydb URI scheme.

  >>> client = MontyClient("montydb:///db/repo")

Utilities

Pymongo bson may required.

• montyimport

  Imports content from an Extended JSON file into a MontyCollection instance. The JSON file could be generated from montyexport or mongoexport.

  >>> from montydb import open_repo, utils
  >>> with open_repo("foo/bar"):
  >>>     utils.montyimport("db", "col", "/path/dump.json")
  >>>
  

• montyexport

  Produces a JSON export of data stored in a MontyCollection instance. The JSON file could be loaded by montyimport or mongoimport.

  >>> from montydb import open_repo, utils
  >>> with open_repo("foo/bar"):
  >>>     utils.montyexport("db", "col", "/data/dump.json")
  >>>
  

• montyrestore

  Loads a binary database dump into a MontyCollection instance. The BSON file could be generated from montydump or mongodump.

  >>> from montydb import open_repo, utils
  >>> with open_repo("foo/bar"):
  >>>     utils.montyrestore("db", "col", "/path/dump.bson")
  >>>
  

• montydump

  Creates a binary export from a MontyCollection instance. The BSON file could be loaded by montyrestore or mongorestore.

  >>> from montydb import open_repo, utils
  >>> with open_repo("foo/bar"):
  >>>     utils.montydump("db", "col", "/data/dump.bson")
  >>>
  

• MongoQueryRecorder

  Record MongoDB query results in a period of time. Requires to access databse profiler.

  This works via filtering the database profile data and reproduce the queries of find and distinct commands.

  >>> from pymongo import MongoClient
  >>> from montydb.utils import MongoQueryRecorder
  >>> client = MongoClient()
  >>> recorder = MongoQueryRecorder(client["mydb"])
  >>> recorder.start()
  >>> # Make some queries or run the App...
  >>> recorder.stop()
  >>> recorder.extract()
  {<collection_1>: [<doc_1>, <doc_2>, ...], ...}
  

• MontyList

  Experimental, a subclass of list, combined the common CRUD methods from Mongo's Collection and Cursor.

  >>> from montydb.utils import MontyList
  >>> mtl = MontyList([1, 2, {"a": 1}, {"a": 5}, {"a": 8}])
  >>> mtl.find({"a": {"$gt": 3}})
  MontyList([{'a': 5}, {'a': 8}])
  

Why I did this ?

Mainly for personal skill practicing and fun. I work in VFX industry, some of my production needs (mostly edge-case) requires to run in a limited environment (e.g. outsourced render farms), which may have problem to run or connect a MongoDB instance. And I found this project really helps.

---