setmodule helper method on Settings class

docs/topics/api.rst

@@ -190,6 +190,21 @@ Settings API
            :attr:`~scrapy.settings.SETTINGS_PRIORITIES` or an integer
        :type priority: string or int
 
+    .. method:: setmodule(module, priority='project')
+
+       Store settings from a module with a given priority.
+
+       This is a helper function that calls
+       :meth:`~scrapy.settings.Settings.set` for every globally declared
+       uppercase variable of ``module`` with the provided ``priority``.
+
+       :param module: the module or the path of the module
+       :type module: module object or string
+
+       :param priority: the priority of the settings. Should be a key of
+           :attr:`~scrapy.settings.SETTINGS_PRIORITIES` or an integer
+       :type priority: string or int
+
     .. method:: get(name, default=None)
 
        Get a setting value without affecting its original type.

scrapy/settings/__init__.py

@@ -1,5 +1,6 @@
 import six
 import json
+from importlib import import_module
 
 from scrapy.utils.deprecate import create_deprecated_class
 
@@ -43,8 +44,7 @@ class Settings(object):
 
     def __init__(self, values=None, priority='project'):
         self.attributes = {}
-        for name, defvalue in iter_default_settings():
-            self.set(name, defvalue, 'default')
+        self.setmodule(default_settings, priority='default')
         if values is not None:
             self.setdict(values, priority)
 
@@ -101,6 +101,13 @@ class Settings(object):
         for name, value in six.iteritems(values):
             self.set(name, value, priority)
 
+    def setmodule(self, module, priority='project'):
+        if isinstance(module, six.string_types):
+            module = import_module(module)
+        for key in dir(module):
+            if key.isupper():
+                self.set(key, getattr(module, key), priority)
+
 
 class CrawlerSettings(Settings):
 

scrapy/tests/test_settings/__init__.py

@@ -101,6 +101,41 @@ class SettingsTest(unittest.TestCase):
                      mock.call('TEST_2', 'value2', 10)]
             mock_set.assert_has_calls(calls, any_order=True)
 
+    def test_setmodule_only_load_uppercase_vars(self):
+        class ModuleMock():
+            UPPERCASE_VAR = 'value'
+            MIXEDcase_VAR = 'othervalue'
+            lowercase_var = 'anothervalue'
+
+        self.settings.attributes = {}
+        self.settings.setmodule(ModuleMock(), 10)
+        self.assertIn('UPPERCASE_VAR', self.settings.attributes)
+        self.assertNotIn('MIXEDcase_VAR', self.settings.attributes)
+        self.assertNotIn('lowercase_var', self.settings.attributes)
+        self.assertEqual(len(self.settings.attributes), 1)
+
+    def test_setmodule_alias(self):
+        with mock.patch.object(self.settings, 'set') as mock_set:
+            self.settings.setmodule(default_settings, 10)
+            mock_set.assert_called_with('TEST_DEFAULT', 'defvalue', 10)
+
+    def test_setmodule_by_path(self):
+        self.settings.attributes = {}
+        self.settings.setmodule(default_settings, 10)
+        ctrl_attributes = self.settings.attributes.copy()
+
+        self.settings.attributes = {}
+        self.settings.setmodule(
+            'scrapy.tests.test_settings.default_settings', 10)
+
+        self.assertItemsEqual(six.iterkeys(self.settings.attributes),
+                              six.iterkeys(ctrl_attributes))
+
+        for attr, ctrl_attr in zip(six.itervalues(self.settings.attributes),
+                                   six.itervalues(ctrl_attributes)):
+            self.assertEqual(attr.value, ctrl_attr.value)
+            self.assertEqual(attr.priority, ctrl_attr.priority)
+
     def test_get(self):
         test_configuration = {
             'TEST_ENABLED1': '1',