load multiples settings separated by comma (like a pipeline)

simple_settings/core.py

@@ -4,29 +4,37 @@
 import sys
 
 
+def _get_settings_from_cmd_line():
+    for arg in sys.argv[1:]:
+        if arg.startswith('--settings'):
+            try:
+                return arg.split('=')[1]
+            except IndexError:
+                return None
+
+
 class _Settings(object):
+
     def __init__(self):
         self._dict = {}
         self._setup()
 
     def _setup(self):
-        self._settings_module = self._get_settings_from_cmd_line()
-        if not self._settings_module:
-            self._settings_module = os.environ.get('settings')
-        if not self._settings_module:
+        settings_value = _get_settings_from_cmd_line()
+        if settings_value is None:
+            settings_value = os.environ.get('settings')
+        if settings_value is None:
             raise RuntimeError('Settings are not configured')
-        self._load_settings_module()
-
-    def _get_settings_from_cmd_line(self):
-        for arg in sys.argv:
-            if arg.startswith('--settings'):
-                try:
-                    return arg.split('=')[1]
-                except IndexError:
-                    return None
-
-    def _load_settings_module(self):
-        module = importlib.import_module(self._settings_module)
+
+        self._settings_list = settings_value.split(',')
+        self._load_settings_pipeline()
+
+    def _load_settings_pipeline(self):
+        for settings_module in self._settings_list:
+            self._load_python_module(settings_module)
+
+    def _load_python_module(self, settings_module):
+        module = importlib.import_module(settings_module)
         for setting in dir(module):
             value = os.environ.get(setting, getattr(module, setting))
             self._dict[setting] = value

tests/samples/without_import.py

@@ -0,0 +1,5 @@
+# -*- coding: utf-8 -*-
+
+
+SOME_TEXT = u'some text'
+SIMPLE_INTEGER = 2

tests/test_settings.py

@@ -5,12 +5,14 @@
 
 
 def get_settings_by_cmd_line(module_name):
-    with patch.object(sys, 'argv', ['--settings={}'.format(module_name)]):
+    with patch.object(
+        sys, 'argv', ['', '--settings={}'.format(module_name)]
+    ):
         from simple_settings.core import _Settings
         return _Settings()
 
 
-def get_settings_by_enviroment(module_name):
+def get_settings_by_environment(module_name):
     with patch('os.environ.get') as mock:
         mock.return_value = module_name
         from simple_settings.core import _Settings
@@ -19,20 +21,33 @@ def get_settings_by_enviroment(module_name):
 
 class TestSettings(object):
 
-    def test_should_load_module_by_cmd_line(self):
+    def test_should_read_cmd_line_settings_value(self):
         expect_module = 'tests.samples.simple'
         settings = get_settings_by_cmd_line(expect_module)
 
-        assert settings._settings_module == expect_module
+        assert settings._settings_list == [expect_module]
 
-    def test_should_load_module_by_enviroment(self):
+    def test_should_read_cmd_line_multiples_settings_value(self):
+        expect_modules = 'tests.samples.simple,tests.samples.complex'
+        settings = get_settings_by_cmd_line(expect_modules)
+
+        assert settings._settings_list == expect_modules.split(',')
+
+    def test_should_read_environment_settings_value(self):
         expect_module = 'tests.samples.complex'
         with patch.object(sys, 'argv', []):
-            settings = get_settings_by_enviroment(expect_module)
+            settings = get_settings_by_environment(expect_module)
+
+        assert settings._settings_list == [expect_module]
+
+    def test_should_read_environment_multiples_settings_value(self):
+        expect_module = 'tests.samples.complex,tests.samples.complex'
+        with patch.object(sys, 'argv', []):
+            settings = get_settings_by_environment(expect_module)
 
-        assert settings._settings_module == expect_module
+        assert settings._settings_list == expect_module.split(',')
 
-    def test_simple_settings(self):
+    def test_load_a_simple_module_settings(self):
         settings = get_settings_by_cmd_line('tests.samples.simple')
 
         assert settings.SIMPLE_STRING == u'simple'
@@ -43,20 +58,35 @@ def test_should_inherit_settings(self):
 
         assert settings.APPLICATION_NAME == u'Simple Settings'
 
-    def test_complex_settings(self):
+    def test_should_load_multiple_settings_by_pipeline(self):
+        settings = get_settings_by_cmd_line(
+            'tests.samples.simple,tests.samples.without_import'
+        )
+
+        assert settings.SIMPLE_STRING == u'simple'
+        assert settings.SOME_TEXT == u'some text'
+
+    def test_should_inherit_settings_with_pipeline(self):
+        settings = get_settings_by_cmd_line(
+            'tests.samples.simple,tests.samples.without_import'
+        )
+
+        assert settings.SIMPLE_INTEGER == 2
+
+    def test_load_a_complex_module_settings(self):
         settings = get_settings_by_cmd_line('tests.samples.complex')
 
         assert settings.COMPLEX_DICT['complex'] == 'settings'
         assert settings.COMPLEX_DICT['foo'] == 'bar'
 
-    def test_settings_as_dict(self):
+    def test_read_settings_by_method_as_dict(self):
         settings = get_settings_by_cmd_line('tests.samples.simple')
 
         settings_dict = settings.as_dict()
         assert settings_dict['SIMPLE_STRING'] == u'simple'
         assert settings_dict['SIMPLE_INTEGER'] == 1
 
-    def test_settings_override_by_enviroment(self):
+    def test_setting_override_by_environment(self):
         def _mock_env_side_effect(k, d=None):
             return u'simple from env' if k == 'SIMPLE_STRING' else d
 
@@ -72,13 +102,15 @@ def test_setting_are_not_configured(self):
                 _Settings()
 
     def test_setting_configured_wrong(self):
-        with patch.object(sys, 'argv', ['--settings', 'tests.samples.simple']):
+        with patch.object(
+            sys, 'argv', ['', '--settings', 'tests.samples.simple']
+        ):
             with pytest.raises(RuntimeError):
                 from simple_settings.core import _Settings
                 _Settings()
 
     def test_setting_not_found(self):
-        with patch.object(sys, 'argv', ['--settings=foo']):
+        with patch.object(sys, 'argv', ['', '--settings=foo']):
             with pytest.raises(ImportError):
                 from simple_settings.core import _Settings
                 _Settings()