Stop normalizing lowercase prefixes

The initial inspiration for this feature was the way Viper (a popular Go
package for configuration) handled environment variables. Sadly, our use
cases for prefixes differ enough where modifying the prefix isn't a
viable option. Viper can get away with it since its prefix is only used
to generate its default environment variable names, whereas ours are
used for both generating implicit environment variable names and
configuring explicit ones.
Unless we disallow lowercase environment variables (a bold option
considering no other packages do this), keeping the prefix and passed
name as-is is the best option.

Author: orlnub123

CHANGELOG.md

@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 - Excluded nonupper attributes from default_settings.
 - Restricted the settings module to the {module}:{class} formatting.
+- Stopped normalizing lowercase prefixes.
 
 ## [0.1.3] - Unreleased
 

class_settings/env.py

@@ -8,7 +8,7 @@
 
 from . import parsers
 from .options import Options
-from .utils import missing, normalize_prefix
+from .utils import missing
 
 
 class Env:
@@ -42,7 +42,7 @@ def __call__(self, name=None, *, prefix=missing, default=missing, optional=False
         if name is None or optional:
             kwargs = {"name": name, "prefix": prefix, "default": default}
             return DeferredEnv(self, kwargs=kwargs, optional=optional)
-        prefix = normalize_prefix(
+        prefix = (
             prefix
             if prefix is not missing
             else self._prefix
@@ -77,7 +77,6 @@ def read_env(file=None):
 
     @contextlib.contextmanager
     def prefixed(self, prefix):
-        prefix = normalize_prefix(prefix)
         old_prefix = self._prefix
         if not old_prefix or prefix is None:
             self._prefix = prefix

class_settings/options.py

@@ -5,7 +5,7 @@ class Options:
     defaults = {
         "default_settings": global_settings,
         "inject_settings": False,
-        "env_prefix": "django",
+        "env_prefix": "DJANGO_",
     }
 
     def __init__(self, meta):

class_settings/utils.py

@@ -4,11 +4,3 @@ def __bool__(self):
 
 
 missing = Missing()
-
-
-def normalize_prefix(prefix):
-    if prefix is None:
-        return prefix
-    if prefix.islower() and not prefix.endswith("_"):
-        prefix += "_"
-    return prefix.upper()

tests/test_env.py

@@ -40,7 +40,7 @@ class TestSettings(Settings):
     )
     def test_env_prefix(self, env):
         class TestSettings(Settings):
-            SECRET_KEY = env("SECRET_KEY", prefix="django")
+            SECRET_KEY = env("SECRET_KEY", prefix="DJANGO_")
             CUSTOM = env("CUSTOM", prefix="CUSTOM")
 
         settings = TestSettings()
@@ -79,7 +79,7 @@ class TestSettings(Settings):
     )
     def test_env_prefixed(self, env):
         class TestSettings(Settings):
-            with env.prefixed("django"):
+            with env.prefixed("DJANGO_"):
                 SECRET_KEY = env("SECRET_KEY")
                 with env.prefixed("CUSTOM"):
                     CUSTOM = env("CUSTOM")
@@ -211,7 +211,7 @@ class TestSettings(Settings):
             CUSTOM = env("CUSTOM")
 
             class Meta:
-                env_prefix = "custom"
+                env_prefix = "CUSTOM_"
 
         settings = TestSettings()