initial commit

.gitignore

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+# Created by .ignore support plugin (hsz.mobi)
+### Python template
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit tests / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*,cover
+.hypothesis/
+coverage/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# SageMath parsed files
+*.sage.py
+
+# dotenv
+.env
+
+# virtualenv
+.venv
+venv/
+ENV/
+
+# Spyder project settings
+.spyderproject
+
+# Rope project settings
+.ropeproject
+### JetBrains template
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff:
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/dictionaries
+
+# Sensitive or high-churn files:
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.xml
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+
+# Gradle:
+.idea/**/gradle.xml
+.idea/**/libraries
+
+# Mongo Explorer plugin:
+.idea/**/mongoSettings.xml
+
+## File-based project format:
+*.iws
+
+## Plugin-specific files:
+
+# IntelliJ
+/out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+## Custom
+/.idea/

LICENSE

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+ISC License
+
+Copyright (c) 2017, Paweł Zadrożny @pawelzny <[email protected]>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

README.rst

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+============
+Value Object
+============
+
+:Info: DDD Value Objects implementation.
+:Author: Paweł Zadrożny <[email protected]>
+
+Installation:
+=============
+
+.. code:: bash
+    pip install vo
+
+
+**Package**: https://pypi.python.org/pypi/vo
+
+
+Example
+=======
+
+.. code:: python
+    from vo.Value import Value
+
+    value1 = Value(test=True, some_text="I am some text string")
+    value2 = Value(some_text="I am some text string", test=True)
+
+    assert(value1 == value2)  # True
+
+    value1.set("extra_attr", "whatever")
+
+    assert(value1 == value2)  # False
+    assert("whatever" == value1.get("extra_attr"))  # True
+    assert("default value" == value2.get("extra_attr", "default value"))  # True

bin/run_tests.sh

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+#!/usr/bin/env bash
+
+# Get absolute path to this script directory
+bin_dir=$(dirname $(readlink -f "$0"))
+package_dir=${bin_dir}/../
+coverage_dir=${package_dir}/tests/coverage
+
+# Run tests with nose test runner
+nosetests --where=${package_dir} \
+          --with-coverage --cover-erase --cover-branches \
+          --cover-html --cover-html-dir=${coverage_dir} \
+          --cover-xml --cover-xml-file=${package_dir}/coverage.xml \
+          --stop

setup.py

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+# -*- coding: utf-8 -*-
+
+from setuptools import setup, find_packages
+
+
+with open('README.rst') as f:
+    readme = f.read()
+
+with open('LICENSE') as f:
+    license = f.read()
+
+setup(name='vo',
+      version='0.1.0',
+      description='DDD Value Objects implementation',
+      long_description=readme,
+      keywords='value data object DDD',
+      author='Pawel Zadrozny @pawelzny',
+      author_email='[email protected]',
+      url='https://github.com/pawelzny/vo',
+      license=license,
+      test_suite='nose.collector',
+      tests_require=['nose', 'coverage'],
+      packages=find_packages(exclude=('tests', 'docs', 'bin')),
+      zip_safe=False)

tests/test_Value.py

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+import unittest
+
+from vo.Value import Value
+
+
+class ValueTest(unittest.TestCase):
+    def test_assign_kwargs(self):
+        value = Value(test=True, text="Some text")
+
+        self.assertTrue(value.test)
+        self.assertEqual('Some text', value.text)
+
+    def test_equal(self):
+        v1 = Value(text="first text", other_attr=1243)
+        v2 = Value(other_attr=1243, text="first text")
+
+        self.assertEqual(v1, v2)
+        self.assertEqual(hash(v1), hash(v2))
+
+        v1.new_attr = True
+        v2.new_attr = False
+
+        self.assertNotEqual(v1, v2)
+        self.assertNotEqual(hash(v1), hash(v2))
+
+    def test_setter(self):
+        v1 = Value()
+        v1.set(some_attr="I am some attribute")
+        self.assertEqual('I am some attribute', v1.get('some_attr'))
+
+        v1.set(some_attr="Now i am different")
+        self.assertEqual("Now i am different", v1.some_attr)
+
+    def test_getter(self):
+        v1 = Value()
+        self.assertEqual("Example string", v1.get('undefined_attr', "Example string"))

vo/Value.py

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+import hashlib
+
+
+class Value:
+    """
+    Basic implementation of DDD Value Object. These objects
+    are meant to holds data only without any business logic.
+    When data has no identifier so it is not an Entity,
+    there comes Value Objects.
+    
+    Value Objects are consider same if they holds the same
+    data even if allocated in different parts of memory.
+    
+    :Example:
+    
+    import vo
+    
+    value1 = vo.Value(name="test value", test=True)
+    value2 = vo.Value(test=True, name="test value")
+    assert(value1 == value2)  # True
+    
+    value1.set(extra="extra data")
+    assert(value1 == value2)  # False
+    """
+
+    @staticmethod
+    def to_bytes(string):
+        """
+        Converts string to byte string
+        :param 
+            string (str): String or number to convert
+        :return
+            (str): Byte string
+        """
+
+        return bytes(repr(string), 'utf-8')
+
+    def __init__(self, **kwargs):
+        """
+        Dynamically add all kwargs to self dictionary.
+        :param 
+            kwargs: Key-value pairs 
+        """
+
+        self.set(**kwargs)
+
+    def __eq__(self, other):
+        """
+        Predicate if checksum of Value Objects are the same.
+        :param 
+            other: ValueObject
+        :return
+            (bool): Boolean
+        """
+
+        return self.checksum() == other.checksum()
+
+    def __ne__(self, other):
+        """
+        Predicate if checksum of Value Objects are different.
+        :param 
+            other: ValueObject
+        :return
+            (bool): Boolean 
+        """
+
+        return self.checksum() != other.checksum()
+
+    def __hash__(self):
+        """
+        Returns hash of checksum
+        :return 
+            (int): Integer representing object Hash
+        """
+
+        return hash(self.checksum())
+
+    def set(self, **kwargs):
+        """
+        Set additional attributes from kwargs
+        :param 
+            kwargs: 
+        :return 
+            (self): Returns self to allow method chaining.
+        """
+
+        self.__dict__.update(kwargs)
+
+        return self
+
+    def get(self, name, default=None):
+        """
+        Gets attribute value or default if not exists.
+        :param 
+            name (str): Attribute name
+            default (any): Default value
+        :return
+            (any): Existing attribute value or default
+        """
+
+        return getattr(self, name, default)
+
+    def checksum(self):
+        """
+        Computes and returns sha224 string from self dict items.
+        :return
+            (str): SHA224 string representing checksum of object values.
+        """
+
+        ck_sum = Value.to_bytes('checksum:')
+        for key, value in sorted(self.__dict__.items()):
+            ck_sum += Value.to_bytes(str(key) + str(value))
+
+        return hashlib.sha224(ck_sum).hexdigest()