simple config

+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# 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 test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pycharm file
+.idea/

+[nosetests]
+verbosity=3
+with-doctest=1
+with-coverage=1

+[style]
+based_on_style = pep8
+spaces_before_comment = 4
+split_before_logical_operator = true
+coalesce_brackets = true
+ALLOW_SPLIT_BEFORE_DICT_VALUE=false

+# simple_config
+
+Python项目的配置信息工具，可以从解析配置文件、环境变量。
+
+## Getting Started
+
+
+### Installing
+
+
+```
+$: git clone git@gitlab.situdata.com:zhouweiqi/simple_config.git
+$: pip install -e simple_config
+```
+
+
+### QuickStart
+
+
+**配置文件**
+
+创建配置文件`test.ini`, 内容如下：
+
+```
+ETCD_HOST=1.1.1.1
+ETCD_PORT=80
+ETCD_PASSWD=0hyxdryq_CZ
+ETCD_USER=test
+HTTP_SERVER=http://test.com
+DEBUG=true
+ALLOWED_HOSTS=*.test.com, api.test.com,  *
+USER_NAME=root
+```
+
+解析配置文件
+
+```python
+In [2]: from simple_config import Config, ConfigAttribute, converter
+In [3]: class ProjectConfig(Config):
+   ...:     ETCD_HOST = ConfigAttribute('ETCD_HOST')
+   ...:     ETCD_PORT = ConfigAttribute('ETCD_PORT', get_converter=int)
+   ...:     ETCD_USER = ConfigAttribute('ETCD_USER')
+   ...:     ETCD_PASSWD = ConfigAttribute('ETCD_PASSWD')
+   ...: 
+   ...:     HTTP_SERVER = ConfigAttribute(
+   ...:         'HTTP_SERVER', get_converter=converter.server)
+   ...: 
+   ...:     DEBUG = ConfigAttribute('DEBUG', get_converter=converter.boolean)
+   ...:     ALIAS_DEBUG = ConfigAttribute('DEBUG', get_converter=converter.boolean)
+   ...: 
+   ...:     ALLOWED_HOSTS = ConfigAttribute(
+   ...:         'ALLOWED_HOSTS', get_converter=converter.Csv())
+   ...: 
+   ...: 
+   ...: config = ProjectConfig(defaults={'DEBUG': False})
+
+In [4]: config.DEBUG
+Out[4]: False
+
+In [5]: config.from_env_file('test.ini')
+
+In [6]: config.DEBUG
+Out[6]: True
+
+In [7]: config.ETCD_PORT
+Out[7]: 80
+
+In [8]: config.get_namespace('ETCD_')
+Out[8]: {'host': '1.1.1.1', 'passwd': '0hyxdryq_CZ', 'port': 80, 'user': 'test'}
+
+In [9]: config.ALLOWED_HOSTS
+Out[9]: ['*.test.com', 'api.test.com', '*']
+
+In [10]: config.ALIAS_DEBUG
+Out[10]: True
+
+In [11]: config.USER_NAME  # 获取配置文件中有，但是Config没有声明的配置
+Out[11]: 'root'
+
+In [12]: config.HTTP_SERVER
+Out[12]: Server(scheme='http', host='test.com', port=80)
+
+```
+
+
+**常量**
+
+创建文件`const.py`, 内容如下
+
+```python
+import sys
+from simple_config import Const
+
+A = 1
+B = 2
+
+
+sys.modules[__name__] = Const.from_current_module(__name__)
+```
+
+加载常量
+
+```python
+In [1]: import const
+In [2]: const
+Out[2]: <simple_config.Const at 0x7fc59c9475c0>
+In [3]: const?
+Type:        Const
+String form: <simple_config.Const object at 0x7fc59c9475c0>
+Docstring:   <no docstring>
+In [4]: const.A
+Out[4]: 1
+In [5]: const.B
+Out[5]: 2
+In [6]: const.A = 3  # 不能修改已有变量值
+---------------------------------------------------------------------------
+ConstError                                Traceback (most recent call last)
+<ipython-input-6-d1e1d5d0fa5a> in <module>
+----> 1 const.A = 3
+
+~/code/simple_config/simple_config/__init__.py in __setattr__(self, name, value)
+     14     def __setattr__(self, name, value):
+     15         if name in self.__dict__:
+---> 16             raise self.ConstError("Can't change const.{}".format(name))
+     17         if not name.isupper():
+     18             raise self.ConstCaseError(
+
+ConstError: Can't change const.A
+```
+
+
+
+## Test
+
+1. 安装依赖
+
+    ```bash
+    $ pip install nose coverage
+    ```
+
+2. 运行测试
+
+    ```
+    nosetests -c .setup.cfg
+    ```

+coverage==4.5.2
+nose==1.3.7

+import setuptools
+import simple_config
+
+with open('README.md', 'r', encoding='utf8') as fh:
+    long_description = fh.read()
+
+setuptools.setup(
+    name="simple_config",
+    version=simple_config.__version__,
+    author="clay",
+    author_email="zhouweiqi@situdata.com",
+    description="A small tool to parse and store project config",
+    long_description=long_description,
+    long_description_content_type="text/markdown",
+    packages=setuptools.find_packages(),
+    classifiers=[
+        "Programming Language :: Python :: 3",
+        "Operating System :: OS Independent",
+    ],
+)

+import sys
+
+from .core import Config
+from .core import Attribute as ConfigAttribute
+
+
+class Const(object):
+    class ConstError(TypeError):
+        pass
+
+    class ConstCaseError(ConstError):
+        pass
+
+    def __setattr__(self, name, value):
+        if name in self.__dict__:
+            raise self.ConstError("Can't change const.{}".format(name))
+        if not name.isupper():
+            raise self.ConstCaseError(
+                "const name {} is not all uppercase".format(name))
+        self.__dict__[name] = value
+
+    @classmethod
+    def from_current_module(cls, name):
+        current_module = sys.modules[name]
+        _const = cls()
+        for key in dir(current_module):
+            if not key.isupper():
+                continue
+            setattr(_const, key, getattr(current_module, key))
+        return _const
+
+
+__name__ = "simple_config"
+__all__ = ('Config', 'ConfigAttribute', 'const')
+__version__ = '1.2'

+from collections import namedtuple
+import re
+import string
+from shlex import shlex
+
+from .exceptions import ConvertError
+
+__all__ = ('host_port', 'server', 'Csv')
+
+Server = namedtuple('Server', 'scheme host port')
+
+host_port_pattern = re.compile(
+    r'^(?P<host>[0-9a-zA-Z\-.]+)(?:\:(?P<port>\d{1,5}))?$')
+
+
+def host_port(string):
+    """
+    解析"host:port"字符串
+
+    >>> host_port('dev.some-host.org:60000')
+    Server(scheme=None, host='dev.some-host.org', port=60000)
+    >>> host_port('8.8.8.8:8080')
+    Server(scheme=None, host='8.8.8.8', port=8080)
+    >>> host_port('8.8.8.8')
+    Server(scheme=None, host='8.8.8.8', port=None)
+    >>> res = host_port('dev.some-host.org:600000')
+    Traceback (most recent call last):
+        ...
+    simple_config.exceptions.ConvertError: invalid host_port \
+string: dev.some-host.org:600000
+
+    """
+    match = host_port_pattern.match(string)
+    if not match:
+        raise ConvertError('invalid host_port string: %s' % string)
+    port = match.group('port') and int(match.group('port'))
+    return Server(None, match.group('host'), port)
+
+
+http_server_pattern = re.compile(
+    r'^(?P<schema>https?)://(?P<host>[0-9a-zA-Z\-.]+)(?:\:(?P<port>\d{1,5}))?$'
+)
+
+
+def server(string):
+    """
+    解析"http://host:port"字符串
+
+    >>> server('http://dev.some-host.org:60000')
+    Server(scheme='http', host='dev.some-host.org', port=60000)
+    >>> server('https://8.8.8.8:8080')
+    Server(scheme='https', host='8.8.8.8', port=8080)
+    >>> server('http://8.8.8.8')
+    Server(scheme='http', host='8.8.8.8', port=80)
+    >>> res = server('dev.some-host.org:600000')
+    Traceback (most recent call last):
+        ...
+    simple_config.exceptions.ConvertError: invalid http_server \
+string: dev.some-host.org:600000
+
+
+    """
+    match = http_server_pattern.match(string)
+    if not match:
+        raise ConvertError('invalid http_server string: %s' % string)
+    port = match.group('port') and int(match.group('port'))
+    if not port:
+        port = 80 if match.group('schema') == 'http' else 443
+    return Server(match.group('schema'), match.group('host'), port)
+
+
+def boolean(instance):
+    """
+    根据输入，返回是否为True
+
+    >>> boolean(True)
+    True
+    >>> boolean('True')
+    True
+    >>> boolean('TRUE')
+    True
+    >>> boolean('false')
+    False
+    >>> boolean(None)
+    Traceback (most recent call last):
+        ...
+    simple_config.exceptions.ConvertError: expected boolean or str, \
+but get <class 'type'>
+
+    """
+    if isinstance(instance, bool):
+        return instance
+    elif isinstance(instance, str):
+        if instance.upper() == 'TRUE':
+            return True
+        return False
+    raise ConvertError('expected boolean or str, but get %s' % type(object))
+
+
+class Csv(object):
+    """
+    Produces a csv parser that return a list of transformed elements.
+
+    origin code is here
+    https://github.com/henriquebastos/python-decouple/blob/master/decouple.py
+    >>> csv = Csv()
+    >>> hosts = "*,*.test.com, demo.test.com   ,test.org"
+    >>> csv(hosts)
+    ['*', '*.test.com', 'demo.test.com', 'test.org']
+    >>> csv = Csv(delimiter=';；')
+    >>> string = 'a;b; c；D'
+    >>> csv(string)
+    ['a', 'b', 'c', 'D']
+    >>> hosts = "*,*.test.com, demo.test.com   ,test.org"
+    >>> csv(hosts)
+    ['*,*.test.com, demo.test.com   ,test.org']
+    """
+
+    def __init__(self,
+                 cast=str,
+                 delimiter=',',
+                 strip=string.whitespace,
+                 post_process=list):
+        """
+        Parameters:
+        cast -- callable that transforms the item just before
+                it's added to the list.
+        delimiter -- string of delimiters chars passed to shlex.
+        strip -- string of non-relevant characters to be passed to
+                 str.strip after the split.
+        """
+        self.cast = cast
+        self.delimiter = delimiter
+        self.strip = strip
+        self.post_process = post_process
+
+    def __call__(self, value):
+        """The actual transformation"""
+
+        def transform(s):
+            return self.cast(s.strip(self.strip))
+
+        splitter = shlex(value, posix=True)
+        splitter.whitespace = self.delimiter
+        splitter.whitespace_split = True
+
+        return self.post_process(transform(s) for s in splitter)

+from configparser import ConfigParser
+import os
+import re
+import warnings
+
+from .exceptions import (FileDoesNotExist, VariableNotExist, NotConfigured,
+                         InvalidConfig)
+
+
+class Attribute(object):
+    """
+
+    >>> from .converter import boolean
+    >>> class TestConfig(Config):
+    ...     DEBUG = Attribute('DEBUG', boolean)
+    ...
+    >>> config = TestConfig()
+    >>> config.DEBUG
+    Traceback (most recent call last):
+        ....
+    simple_config.exceptions.NotConfigured: value of 'DEBUG' has not been set
+    >>> config = TestConfig(defaults={'debug':False})
+    >>> config.DEBUG
+    False
+    >>> config.DEBUG = False
+    >>> config._raw_config['debug']
+    Traceback (most recent call last):
+        ....
+    KeyError: 'debug'
+    >>> config._raw_config['DEBUG']
+    False
+    """
+
+    def __init__(self, name, get_converter=None):
+        if name.upper() != name:
+            warnings.warn('upper case name is expected')
+        self.__name__ = name.upper()
+        self.get_converter = get_converter
+
+    def __get__(self, obj, type=None):
+        if obj is None:
+            return self
+        try:
+            rv = obj._raw_config[self.__name__]
+        except KeyError:
+            raise NotConfigured(
+                "value of '%s' has not been set" % self.__name__)
+        if self.get_converter is not None:
+            rv = self.get_converter(rv)
+        return rv
+
+    def __set__(self, obj, value):
+        obj._raw_config[self.__name__] = value
+
+
+class Environment(dict):
+    def __init__(self, *args, **kwargs):
+        super(Environment, self).__init__(*args, **kwargs)
+
+    @classmethod
+    def from_env_file(cls, filename, load_env=False):
+        """从文件中加载环境变量
+        """
+        if not os.path.exists(filename):
+            raise FileDoesNotExist('cannot find file: %s' % filename)
+        with open(filename, 'r', encoding='utf8') as f:
+            lines = f.readlines()
+        dct = dict(os.environ) if load_env else {}
+
+        for line in lines:
+            if line.startswith('#'):
+                continue
+            if '=' not in line:
+                if re.match(r'^\s*$', line):
+                    continue
+                raise InvalidConfig("config line should contain '='")
+            key, value = line.strip().split('=', 1)
+            if value[0] == value[-1] and value[0] in ('\'', '"'):
+                warnings.warn('There is no need to quote string')
+            dct[key] = value
+        return cls(dct)
+
+    @classmethod
+    def from_env(cls):
+        return cls(dict(os.environ))
+
+
+class Config(object):
+    INI_SECTION_NAME = 'settings'
+
+    def __init__(self, defaults=None):
+        self._raw_config = {}
+        defaults and self._update_config(**defaults)
+
+    def from_ini(self, filename):
+        """
+
+        >>> config = Config(defaults={'DBEUG': True})
+        >>> from tempfile import TemporaryFile
+        >>> filename = TemporaryFile().name
+        >>> with open(filename, 'w', encoding='utf8') as f:
+        ...     f.write('[settings]\\ndebug=false\\n')
+        23
+        >>> config.from_ini(filename)
+        >>> config._raw_config['DEBUG']
+        'false'
+        >>> with open(filename, 'w', encoding='utf8') as f:
+        ...     f.write('[settings]\\ndebug=True\\n')
+        22
+        >>> config.from_ini(filename)
+        >>> config._raw_config['DEBUG']
+        'True'
+        >>> os.remove(filename)
+        """
+        config = ConfigParser()
+        with open(filename, 'r', encoding='utf8') as f:
+            config.read_file(f)
+        self._update_config(**config[self.INI_SECTION_NAME])
+
+    def from_env_file(self, filename, load_env=False):
+        """
+
+        >>> config = Config(defaults={'DBEUG': True})
+        >>> from tempfile import TemporaryFile
+        >>> filename = TemporaryFile().name
+        >>> with open(filename, 'w', encoding='utf8') as f:
+        ...     f.write('debug=false')
+        11
+        >>> config.from_env_file(filename)
+        >>> config._raw_config['DEBUG']
+        'false'
+        >>> with open(filename, 'w', encoding='utf8') as f:
+        ...     f.write('debug=True')
+        10
+        >>> config.from_env_file(filename)
+        >>> config._raw_config['DEBUG']
+        'True'
+        >>> os.remove(filename)
+        """
+        self._update_config(**Environment.from_env_file(
+            filename, load_env=load_env))
+
+    def from_env_var(self, variable, errors='strict'):
+        environ = Environment.from_env()
+        value = environ.get(variable)
+        if value is None and errors == 'strict':
+            raise VariableNotExist('cannot get %s from env' % variable)
+        self._update_config(**{variable: value})
+
+    def from_object(self, obj):
+        for key in dir(obj):
+            if key.isupper():
+                self._update_config(**{key: getattr(obj, key)})
+
+    def from_dict(self, dct):
+        """
+        >>> from .converter import boolean
+        >>> class NewConfig(Config):
+        ...     DEBUG = Attribute('DEBUG', get_converter=boolean)
+        ...
+        >>> config = NewConfig()
+        >>> config.DEBUG
+        Traceback (most recent call last):
+            ....
+        simple_config.exceptions.NotConfigured: \
+value of 'DEBUG' has not been set
+        >>> config.from_dict({'debug': 'true'})
+        >>> config.DEBUG
+        True
+        >>> config.from_dict({'Debug': ''})
+        >>> config.DEBUG
+        False
+
+        """
+        self._update_config(**dct)
+
+    def _update_config(self, **kwargs):
+        for key, value in kwargs.items():
+            self._raw_config[key.upper()] = value
+
+    def __setattr__(self, key, value):
+        """
+        >>> config = Config()
+        >>> config._raw_config['DEBUG']
+        Traceback (most recent call last):
+            ....
+        KeyError: 'DEBUG'
+        >>> config.DEBUG = False
+        >>> config._raw_config
+        {'DEBUG': False}
+        """
+        pre_fields = ('_raw_config', )
+        if key in pre_fields:
+            super().__setattr__(key, value)
+        else:
+            if key.upper() != key:
+                warnings.warn('upper case attribute is expected')
+            key = key.upper()
+            self._update_config(**{key: value})
+
+    def get_namespace(self, namespace, lowercase=True, trim_namespace=True):
+        """
+        >>> config = Config(
+        ...     defaults={'A_ID': 1, 'A_NAME': 2, 'A_CITY': 3, 'B_ID': 2})
+        >>> config.get_namespace('A') == {'_id': 1, '_name': 2, '_city': 3}
+        True
+        >>> config.get_namespace('A_') == {'id': 1, 'name': 2, 'city': 3}
+        True
+        >>> config.get_namespace('A_', lowercase=False) \\
+        ...     == {'ID': 1, 'NAME': 2, 'CITY': 3}
+        True
+        >>> config.get_namespace(
+        ...        'A_', lowercase=False, trim_namespace=False) \\
+        ...     == {'A_ID': 1, 'A_NAME': 2, 'A_CITY': 3}
+        True
+        """
+        dct = {}
+        for key in self._raw_config.keys():
+            origin_key = key
+            if not key.startswith(namespace):
+                continue
+            if trim_namespace:
+                key = key[len(namespace):]
+            # if lowercase:
+            #     key = key.lower()
+            dct[key] = getattr(self, origin_key)
+        return dct
+
+    def __getattr__(self, key):
+        try:
+            return self._raw_config[key]
+        except KeyError:
+            raise AttributeError("'%s' object has no attribute '%s'" %
+                                 (self.__class__, key))

+class BaseError(Exception):
+    pass
+
+
+class ConvertError(BaseError):
+    pass
+
+
+class FileDoesNotExist(BaseError):
+    pass
+
+
+class VariableNotExist(BaseError):
+    pass
+
+
+class NotConfigured(BaseError):
+    pass
+
+
+class InvalidConfig(BaseError):
+    pass

+import sys
+
+from simple_config import Const
+
+
+A = 1
+A = 2
+# b = 1
+
+
+sys.modules[__name__] = Const.from_current_module(__name__)

+[settings]
+ETCD_HOST=1.1.1.1
+ETCD_PORT=80
+ETCD_PASSWD=0hyxdryq_CZ
+ETCD_USER=test
+
+HTTP_SERVER=http://test.com
+
+DEBUG=true
+
+ALLOWED_HOSTS=*.test.com, api.test.com,  *
+
+USER_NAME=root
+     root
+    root
+      root
+

+import os
+
+from simple_config import Config, ConfigAttribute, converter
+from simple_config import exceptions
+
+file_dir = os.path.dirname(os.path.abspath(__file__))
+
+
+class ProjectConfig(Config):
+    ETCD_HOST = ConfigAttribute('ETCD_HOST')
+    ETCD_PORT = ConfigAttribute('ETCD_PORT', get_converter=int)
+    ETCD_USER = ConfigAttribute('ETCD_USER')
+    ETCD_PASSWD = ConfigAttribute('ETCD_PASSWD')
+
+    HTTP_SERVER = ConfigAttribute(
+        'HTTP_SERVER', get_converter=converter.server)
+
+    DEBUG = ConfigAttribute('DEBUG', get_converter=converter.boolean)
+    ALIAS_DEBUG = ConfigAttribute('DEBUG', get_converter=converter.boolean)
+
+    ALLOWED_HOSTS = ConfigAttribute(
+        'ALLOWED_HOSTS', get_converter=converter.Csv())
+
+
+def test_defaults():
+    config = ProjectConfig(defaults={'DEBUG': False, 'ETCD_HOST': 'test'})
+    assert config.DEBUG is False
+    assert config.ALIAS_DEBUG is False
+    assert config.ETCD_HOST == 'test'
+    try:
+        config.ETCD_PORT
+    except exceptions.NotConfigured:
+        pass
+    else:
+        raise Exception('exception is expected')
+
+
+def test_env_file():
+    config = ProjectConfig(defaults={'DEBUG': False})
+    assert config.DEBUG is False
+    config.from_env_file(os.path.join(file_dir, 'test_env'))
+    assert config.DEBUG is True
+    assert config.ETCD_PORT == 80
+    assert config.get_namespace('ETCD_') == {
+        'host': '1.1.1.1',
+        'passwd': '0hyxdryq_CZ',
+        'port': 80,
+        'user': 'test'
+    }
+    assert config.ALLOWED_HOSTS == ['*.test.com', 'api.test.com', '*']
+    assert config.ALIAS_DEBUG is True
+    assert config.USER_NAME == 'root'
+
+
+def test_ini():
+    config = ProjectConfig(defaults={'DEBUG': False})
+    assert config.DEBUG is False
+    config.from_ini(os.path.join(file_dir, 'test.ini'))
+    assert config.DEBUG is True
+    assert config.ETCD_PORT == 80
+    assert config.get_namespace('ETCD_') == {
+        'host': '1.1.1.1',
+        'passwd': '0hyxdryq_CZ',
+        'port': 80,
+        'user': 'test'
+    }
+    assert config.ALLOWED_HOSTS == ['*.test.com', 'api.test.com', '*']
+    assert config.ALIAS_DEBUG is True
+    assert config.USER_NAME == 'root\nroot\nroot\nroot'

+import importlib.machinery
+import os
+
+filename = os.path.join(
+    os.path.dirname(os.path.abspath(__file__)), '_const_demo.py')
+
+loader = importlib.machinery.SourceFileLoader('const_demo', filename)
+const_demo = loader.load_module()
+
+
+def test_const():
+    # 变量只能被赋值一次
+    const_demo.B = 2
+    try:
+        const_demo.B = 3
+    except const_demo.ConstError:
+        pass
+    else:
+        raise Exception('ConstError is expected')
+
+    # module中赋值的变量能够被自动加载
+    assert const_demo.A == 2
+    try:
+        const_demo.A = 2
+    except const_demo.ConstError:
+        pass
+    else:
+        raise Exception('ConstError is expected')
+    assert not hasattr(const_demo, 'b')

+ETCD_HOST=1.1.1.1
+ETCD_PORT=80
+ETCD_PASSWD=0hyxdryq_CZ
+ETCD_USER=test
+
+HTTP_SERVER=http://test.com
+
+DEBUG=true
+
+ALLOWED_HOSTS=*.test.com, api.test.com,  *
+
+USER_NAME=root
+