YORM 1.4

Automatic object-YAML mapping for Python.

Overview

YORM enables automatic, bidirectional, human-friendly mappings of object attributes to YAML files.

Uses beyond typical object serialization and relational mapping include:

• bidirectional conversion between basic YAML and Python types

• attribute creation and type inference for new attributes

• storage of content in text files optimized for version control

• extensible converters to customize formatting on complex classes

View the talk from PyOhio 2015.

Requirements

• Python 3.3+

Installation

Install YORM with pip:

$ pip install YORM

or directly from the source code:

$ git clone https://github.com/jacebrowning/yorm.git
$ cd yorm
$ python setup.py install

Usage

Simply take an existing class:

class Student:
    def __init__(self, name, school, number, year=2009):
        self.name = name
        self.school = school
        self.number = number
        self.year = year
        self.gpa = 0.0

and define an attribute mapping:

import yorm
from yorm.types import String, Integer, Float

@yorm.attr(name=String, year=Integer, gpa=Float)
@yorm.sync("students/{self.school}/{self.number}.yml")
class Student:
    ...

Modifications to each object’s mapped attributes:

>>> s1 = Student("John Doe", "GVSU", 123)
>>> s2 = Student("Jane Doe", "GVSU", 456, year=2014)
>>> s1.gpa = 3

are automatically reflected on the filesytem:

$ cat students/GVSU/123.yml
name: John Doe
gpa: 3.0
school: GVSU
year: 2009

Modifications and new content in each mapped file:

$ echo "name: John Doe
> gpa: 1.8
> year: 2010
" > students/GVSU/123.yml

are automatically reflected in their corresponding object:

>>> s1.gpa
1.8

Revision History

1.4 (2017/04/02)

• Removed warnings about calling save/load unnecessarily.

• Now allowing keyword arguments to be passed to class construction via create and find utilities.

• Now adding additional attributes from __init__ on AttributeDictionary.

  • NOTE: For this feature to work, __init__ must not use positional arguments.

• DEPRECIATION: Renamed ModelMixin.new to ModelMixin.create.

1.3 (2017/01/24)

• Optimized the formatting of empty lists to create consistent diffs.

• Added ModelMixin to add ORM methods to mapped classes.

1.2 (2017/01/06)

• Updated base class to hide pytest traceback in wrapped methods.

1.1 (2016/10/22)

• Added data property to Mapper as a hook for other serialization libraries.

1.0.1 (2016/09/23)

• Fixed handling of mutation methods on list and dict.

1.0 (2016/05/22)

• Initial stable release.

0.8.1 (2016/04/28)

• Now invoking __init__ in Dictionary converters to run custom validations.

0.8 (2016/04/14)

• Replaced all utility functions with ORM-like tools.

• Removed the ability to check for existing files in sync().

• Renamed and consolidated custom exceptions.

• Renamed sync parameter auto=True to auto_save=True.

• Renamed sync parameter strict=True to auto_track=False.

• Added sync parameter auto_create to defer file creation to ORM functions.

0.7.2 (2016/03/30)

• Now preserving order of attr decorators on Dictionary converters.

0.7.1 (2016/03/30)

• Updated String to fetch true and false as strings.

0.7 (2016/03/29)

• Now preserving order of attr decorators.

• Now limiting attr decorator to a single argument.

• Added List.of_type() factory to create lists with less boilerplate.

0.6.1 (2015/02/23)

• Fixed handling of None in NullableString.

0.6 (2015/02/23)

• Added preliminary support for JSON serialization (@pr0xmeh).

• Renamed yorm.converters to yorm.types.

• Now maintaining the signature on mapped objects.

• Disabled attribute inference unless strict=False.

• Fixed formatting of String to only use quotes if absolutely necessary.

0.5 (2015/09/25)

• Renamed yorm.base to yorm.bases.

• Stopped creating files on instantiation when auto=False.

• Now automatically storing on fetch after initial store.

0.4.1 (2015/06/19)

• Fixed attribute loss in non-dict when conversion to dict.

• Now automatically adding missing attributes to mapped objects.

0.4 (2015/05/16)

• Moved all converters into the yorm.converters package.

• Renamed container to containers.

• Renamed Converter to Convertible for mutable types

• Added a new Converter class for immutable types

• Removed the context manager in mapped objects.

• Fixed automatic mapping of nested attributes.

0.3.2 (2015/04/07)

• Fixed object overwrite when calling utilities.update.

0.3.1 (2015/04/06)

• Fixed infinite recursion with properties that rely on other mapped attributes.

0.3 (2015/03/10)

• Updated mapped objects to only read from the filesystem if there are changes.

• Renamed store to sync_object.

• Renamed store_instances to sync_instances.

• Renamed map_attr to attr.

• Added sync to call sync_object or sync_instances as needed.

• Added update_object and update_file to force synchronization.

• Added update to call update_object and/or update_file as needed.

0.2.1 (2015/02/12)

• Container types now extend their builtin type.

• Added None<Type> extended types with None as a default.

• Added AttributeDictionary with keys available as attributes.

• Added SortedList that sorts when dumped.

0.2 (2014/11/30)

• Allowing map_attr and store to be used together.

• Allowing Dictionary containers to be used as attributes.

• Fixed method resolution order for modified classes.

• Added a yorm.settings.fake option to bypass the filesystem.

0.1.1 (2014/10/20)

• Fixed typos in examples.

0.1 (2014/09/29)

• Initial release.