Merge pull request #66 from willkg/fast-setup

add fast setup

README.rst

@@ -53,8 +53,28 @@ Most other libraries I looked at had one or more of the following issues:
 Quick start
 ===========
 
-Example
--------
+Fast start example
+------------------
+
+You have an app and want it to look for configuration in an ``.env`` file then
+the environment. You can do this::
+
+    from everett.manager import ConfigManager
+
+    config = ConfigManager.basic_config()
+
+
+Then you can use it like this::
+
+    debug_mode = config('debug', parser=bool)
+
+
+When you outgrow that or need different variations of it, you can change
+that to creating a ``ConfigManager`` from scratch.
+
+
+More control example
+--------------------
 
 We have an app and want to pull configuration from an INI file stored in
 a place specified by ``MYAPP_INI`` in the environment, ``~/.myapp.ini``,
@@ -223,16 +243,16 @@ Components support subclassing, mixins and all that, too.
 Install
 =======
 
-From PyPI
----------
+Install from PyPI
+-----------------
 
 Run::
 
     $ pip install everett
 
 
-For hacking
------------
+Install for hacking
+-------------------
 
 Run::
 

everett/manager.py

@@ -186,6 +186,7 @@ def get_key_from_envs(envs, key, namespace=None):
     """Return the value of a key from the given dict respecting namespaces.
 
     Data can also be a list of data dicts.
+
     """
     # if it barks like a dict, make it a list
     # have to use `get` since dicts and lists
@@ -799,6 +800,47 @@ def __init__(self, environments, doc='', with_override=True):
         self.envs = environments
         self.doc = doc
 
+    @classmethod
+    def basic_config(cls, env_file='.env'):
+        """Returns a basic ConfigManager
+
+        This sets up a ConfigManager that will look for configuration in
+        this order:
+
+        1. environment
+        2. specified ``env_file`` defaulting to ``.env``
+
+        This is for a fast one-line opinionated setup.
+
+        Example::
+
+            from everett.manager import ConfigManager
+
+            config = ConfigManager.basic_config()
+
+
+        This is shorthand for::
+
+            config = ConfigManager(
+                environments=[
+                    ConfigOSEnv(),
+                    ConfigEnvFileEnv(['.env'])
+                ]
+            )
+
+
+        :arg env_file: the name of the env file to use
+
+        :returns: a :py:class:`everett.manager.ConfigManager`
+
+        """
+        return cls(
+            environments=[
+                ConfigOSEnv(),
+                ConfigEnvFileEnv([env_file])
+            ]
+        )
+
     @classmethod
     def from_dict(cls, dict_config):
         """Creates a ConfigManager with specified configuration as a Python dict
@@ -818,7 +860,7 @@ def from_dict(cls, dict_config):
         .. versionadded:: 0.3
 
         """
-        return ConfigManager([ConfigDictEnv(dict_config)])
+        return cls([ConfigDictEnv(dict_config)])
 
     def __call__(self, key, namespace=None, default=NO_VALUE,
                  alternate_keys=NO_VALUE, doc='', parser=str, raise_error=True,

tests/data/.env

@@ -1,4 +1,4 @@
-# dude
+# this is a comment
 LOGLEVEL=walter
 DEBUG=True
 YOURE_NOT_A=golfer

tests/test_manager.py

@@ -19,8 +19,8 @@
     ConfigEnvFileEnv,
     ConfigIniEnv,
     ConfigManager,
-    ConfigObjEnv,
     ConfigOSEnv,
+    ConfigObjEnv,
     ListOf,
     config_override,
     get_key_from_envs,
@@ -464,6 +464,21 @@ def test_config_from_dict():
     assert config('FOO', raise_error=False) == 'bar'
 
 
+def test_basic_config(datadir):
+    os.environ['EVERETT_BASIC_CONFIG_TEST'] = 'foo'
+    env_filename = os.path.join(datadir, '.env')
+    config = ConfigManager.basic_config(env_filename)
+
+    # This doesn't exist in either the environment or the env file
+    assert config('FOO', raise_error=False) is NO_VALUE
+
+    # This exists in the environment
+    assert config('EVERETT_BASIC_CONFIG_TEST') == 'foo'
+
+    # This exists in the env file
+    assert config('LOGLEVEL') == 'walter'
+
+
 def test_config_manager_doc():
     config = ConfigManager(
         [