Settings config inheritance fix #1091

pydantic · Dec 9, 2019 · 8f2e2ab · 8f2e2ab
1 parent 33fee6d
commit 8f2e2ab
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Showing 3 changed files with 17 additions and 1 deletion.
diff --git a/pydantic/env_settings.py b/pydantic/env_settings.py
@@ -66,7 +66,7 @@ class Config:
         @classmethod
         def prepare_field(cls, field: ModelField) -> None:
             env_names: Iterable[str]
-            env = field.field_info.extra.pop('env', None)
+            env = field.field_info.extra.get('env')
             if env is None:
                 if field.has_alias:
                     warnings.warn(

diff --git a/pydantic/fields.py b/pydantic/fields.py
@@ -280,6 +280,7 @@ def infer(
     def set_config(self, config: Type['BaseConfig']) -> None:
         self.model_config = config
         info_from_config = config.get_field_info(self.name)
+        config.prepare_field(self)
         if info_from_config:
             self.field_info.alias = info_from_config.get('alias') or self.field_info.alias or self.name
             self.alias = cast(str, self.field_info.alias)

diff --git a/tests/test_settings.py b/tests/test_settings.py
@@ -376,3 +376,18 @@ class SubSettings(Settings):
     assert SubSettings().dict() == {'foo': 'fff', 'bar': 'bbb', 'spam': 'spam default'}
     env.set('spam', 'sss')
     assert SubSettings().dict() == {'foo': 'fff', 'bar': 'bbb', 'spam': 'sss'}
+
+
+def test_prefix_on_parent(env):
+    class MyBaseSettings(BaseSettings):
+        var: str = 'old'
+
+    class MySubSettings(MyBaseSettings):
+        class Config:
+            env_prefix = 'PREFIX_'
+
+    assert MyBaseSettings().dict() == {'var': 'old'}
+    assert MySubSettings().dict() == {'var': 'old'}
+    env.set('PREFIX_VAR', 'new')
+    assert MyBaseSettings().dict() == {'var': 'old'}
+    assert MySubSettings().dict() == {'var': 'new'}