tinymongo 0.2.0

A flat file drop in replacement for mongodb. Requires Tinydb

Purpose

A simple wrapper to make a drop in replacement for mongodb out of tinydb. This module is an attempt to add an interface familiar to those currently using pymongo.

Status

Unit testing is currently being worked on and functionality is being added to the library. Current coverage is 93%. Current builds tested on Python versions 2.7 and 3.3+.

Installation

The latest stable release can be installed via pip install tinymongo.

The library is currently under rapid development and a more recent version may be desired.

In this case, simply clone this repository, navigate to the root project directory, and pip install -e .

or use pip install -e git+https://github.com/schapman1974/tinymongo.git#egg=tinymongo

This is a pure python distribution and - thus - should require no external compilers or tools besides those contained within Python itself.

Examples

The quick start is shown below. For a more detailed look at tinymongo, take a look at demo.py within the repository.

from tinymongo import TinyMongoClient

# you can include a folder name or absolute path
# as a parameter if not it will default to "tinydb"
connection = TinyMongoClient()

# either creates a new database file or accesses an existing one named `my_tiny_database`
db = connection.my_tiny_database

# either creates a new collection or accesses an existing one named `users`
collection = db.users

# insert data adds a new record returns _id
record_id = collection.insert_one({"username": "admin", "password": "admin", "module":"somemodule"}).inserted_id
user_info = collection.find_one({"_id": record_id})  # returns the record inserted

# you can also use it directly
db.users.insert_one({"username": "admin"})

# returns a list of all users of 'module'
users = db.users.find({'module': 'module'})

#update data returns True if successful and False if unsuccessful
upd = db.users.update_one({"username": "admin"}, {"$set": {"module":"someothermodule"}})

# Sorting users by its username DESC
# omitting `filter` returns all records
db.users.find(sort={'username': -1})

# Pagination of the results
# Getting the first 20 records
db.users.find(sort={'username': -1}, skip=0, limit=20)
# Getting next 20 records
db.users.find(sort={'username': -1}, skip=20, limit=20)

# Getting the total of records
db.users.count()

Custom Storages and Serializers

HINT: Learn more about TinyDB storages and Serializers in documentation

Custom Storages

You have to subclass TinyMongoClient and provide custom storages like CachingMiddleware or other available TinyDB Extension.

Caching Middleware

from tinymongo import TinyMongoClient
from tinydb.storages import JSONStorage
from tinydb.middlewares import CachingMiddleware

class CachedClient(TinyMongoClient):
    """This client has cache"""
    @property
    def _storage(self):
        return CachingMiddleware(JSONStorage)

connection = CachedClient('/path/to/folder')

HINT: You can nest middlewares: FirstMiddleware(SecondMiddleware(JSONStorage))

Serializers

To convert your data to a format that is writable to disk TinyDB uses the Python JSON module by default. It’s great when only simple data types are involved but it cannot handle more complex data types like custom classes.

To support serialization of complex types you can write your own serializers using the tinydb-serialization extension.

First you need to install it pip install tinydb-serialization

Handling datetime objects

You can create a serializer for the python datetime using the following snippet:

from datetime import datetime
from tinydb_serialization import Serializer

class DatetimeSerializer(Serializer):
    OBJ_CLASS = datetime

    def __init__(self, format='%Y-%m-%dT%H:%M:%S', *args, **kwargs):
        super(DatetimeSerializer, self).__init__(*args, **kwargs)
        self._format = format

    def encode(self, obj):
        return obj.strftime(self._format)

    def decode(self, s):
        return datetime.strptime(s, self._format)

NOTE: this serializer is available in tinymongo.serializers.DateTimeSerializer

Now you have to subclass TinyMongoClient and provide customs storage.

from tinymongo import TinyMongoClient
from tinymongo.serializers import DateTimeSerializer
from tinydb_serialization import SerializationMiddleware


class CustomClient(TinyMongoClient):
    @property
    def _storage(self):
        serialization = SerializationMiddleware()
        serialization.register_serializer(DateTimeSerializer(), 'TinyDate')
        # register other custom serializers
        return serialization


connection = CustomClient('/path/to/folder')

Flask-Admin

This extension can work with Flask-Admin which gives a web based administrative panel to your TinyDB. Flask-Admin has features like filtering, search, web forms to perform CRUD (Create, Read, Update, Delete) of the TinyDB records.

You can find the example of Flask-Admin with TinyMongo in Flask-Admin Examples Repository

NOTE: To use Flask-Admin you need to register a DateTimeSerialization as showed in the previous topic.

Contributions

Contributions are welcome! Currently, the most valuable contributions would be:

• adding test cases

• adding functionality consistent with pymongo

• documentation

• identifying bugs and issues

Future Development

I will also be adding support for gridFS by storing the files somehow and indexing them in a db like mongo currently does

More to come……

License

MIT License