Fix to log_level handler, now accepts lowercase ("info")

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## 7.3.0 (unreleased)
+
+- `log_level` accepts lower-cased log level names and rejects invalid
+  names ([#138](https://github.com/sloria/environs/pull/138)).
+  Thanks [gnarvaja](https://github.com/gnarvaja) for the PR.
+
 ## 7.2.0 (2020-02-09)
 
 - Add `dj_cache_url` for caching Django cache URLs (requires installing with `[django]`)

environs/__init__.py

@@ -14,7 +14,7 @@
 import marshmallow as ma
 from dotenv.main import load_dotenv, _walk_to_root
 
-__version__ = "7.2.0"
+__version__ = "7.3.0"
 __all__ = ["EnvError", "Env"]
 
 MARSHMALLOW_VERSION_INFO = tuple(int(part) for part in ma.__version__.split(".") if part.isdigit())
@@ -210,7 +210,8 @@ def _format_num(self, value) -> int:
         try:
             return super()._format_num(value)
         except (TypeError, ValueError) as error:
-            if hasattr(logging, value):
+            value = value.upper()
+            if hasattr(logging, value) and isinstance(getattr(logging, value), int):
                 return getattr(logging, value)
             else:
                 raise ma.ValidationError("Not a valid log level.") from error

tests/test_environs.py

@@ -160,15 +160,19 @@ def test_path_cast(self, set_env, env):
         assert isinstance(res, pathlib.Path)
 
     def test_log_level_cast(self, set_env, env):
-        set_env({"LOG_LEVEL": "WARNING", "LOG_LEVEL_INT": str(logging.WARNING)})
+        set_env({"LOG_LEVEL": "WARNING", "LOG_LEVEL_INT": str(logging.WARNING), "LOG_LEVEL_LOWER": "info"})
         assert env.log_level("LOG_LEVEL_INT") == logging.WARNING
         assert env.log_level("LOG_LEVEL") == logging.WARNING
+        assert env.log_level("LOG_LEVEL_LOWER") == logging.INFO
 
     def test_invalid_log_level(self, set_env, env):
-        set_env({"LOG_LEVEL": "INVALID"})
+        set_env({"LOG_LEVEL": "INVALID", "LOG_LEVEL_BAD": "getLogger"})
         with pytest.raises(environs.EnvError) as excinfo:
             env.log_level("LOG_LEVEL")
         assert "Not a valid log level" in excinfo.value.args[0]
+        with pytest.raises(environs.EnvError) as excinfo:
+            env.log_level("LOG_LEVEL_BAD")
+        assert "Not a valid log level" in excinfo.value.args[0]
 
     @pytest.mark.parametrize("url", ["foo", "42", "foo@bar"])
     def test_invalid_url(self, url, set_env, env):