Merge pull request #44 from deepaerial/feature/env-custom-separator

Added support for custom separator character for nedsted variables.

confz/confz_source.py

@@ -69,6 +69,8 @@ class ConfZEnvSource(ConfZSource):
     file: Optional[Path] = None
     """Built in .env file loading with lower than environment precedence. Uses UTF-8
     for decoding."""
+    nested_separator: str = "."
+    """Separator will be used in nested environment variables."""
 
 
 @dataclass
@@ -86,6 +88,8 @@ class ConfZCLArgSource(ConfZSource):
     remap: Optional[Dict[str, str]] = None
     """Certain command line arguments can be mapped to config arguments with a different
     name. The map does not need to include the two dashes at the beginning."""
+    nested_separator: str = "."
+    """Separator will be used in nested command line arguments."""
 
 
 @dataclass

confz/loaders/cl_arg_loader.py

@@ -25,5 +25,7 @@ def populate_config(cls, config: dict, confz_source: ConfZCLArgSource):
 
                 cl_args[cl_name] = cl_value
 
-        cl_args = cls.transform_nested_dicts(cl_args)
+        cl_args = cls.transform_nested_dicts(
+            cl_args, separator=confz_source.nested_separator
+        )
         cls.update_dict_recursively(config, cl_args)

confz/loaders/env_loader.py

@@ -68,5 +68,7 @@ def populate_config(cls, config: dict, confz_source: ConfZEnvSource):
 
             env_vars[var_name] = origin_env_vars[env_var]
 
-        env_vars = cls.transform_nested_dicts(env_vars)
+        env_vars = cls.transform_nested_dicts(
+            env_vars, separator=confz_source.nested_separator
+        )
         cls.update_dict_recursively(config, env_vars)

confz/loaders/loader.py

@@ -36,13 +36,14 @@ def transform_nested_dicts(
 
         :param dict_in: A dictionary with string-keys.
         :param separator: The string used to separate dict keys.
+                          Default value will no longer be set in a future release.
         :return: The transformed dictionary, splitting keys at the separator and
             creating a new dictionary out of it.
         :raises ConfZUpdateException: If dict keys contradict each other.
         """
         dict_out: Dict[str, Any] = {}
         for key, value in dict_in.items():
-            if separator in key:
+            if separator in key and not key.startswith(separator):
                 inner_keys = key.split(separator)
                 dict_inner = dict_out
                 for idx, inner_key in enumerate(inner_keys):

docs/source/usage/sources_loaders.rst

@@ -15,10 +15,10 @@ There are multiple config sources which support a heterogeneous set of use-cases
   The filename can either be passed directly, via environment variable or via command line argument. The latter cases
   allow to easily configure multiple environments by having a separate file for each environment.
 - :class:`~confz.ConfZEnvSource` allows to load config data from environment variables and .env files. It supports to
-  select the corresponding variables with allow- and deny-lists and with an optional prefix. The variable names are
+  select the corresponding variables with allow- and deny-lists and with an optional prefix and optional custom separator for nested variables. The variable names are
   either inferred from the config name or can be explicitly mapped.
 - :class:`~confz.ConfZCLArgSource` allows to load config data from command line arguments. An optional prefix allows
-  to select only parts of the arguments. The argument names are either inferred from the config name or can be
+  to select only parts of the arguments. Optional custom separator for nested command line arguments is also supported. The argument names are either inferred from the config name or can be
   explicitly mapped.
 - :class:`~confz.ConfZDataSource` allows to define constant config data. This can be very useful for unit tests, see
   :ref:`context_manager`.

tests/loaders/test_cl_arg_loader.py

@@ -41,3 +41,20 @@ def test_remap(monkeypatch):
     config = OuterConfig(config_sources=ConfZCLArgSource(remap={"val1": "inner.attr1"}))
     assert config.inner.attr1 == 1
     assert config.attr2 == 2
+
+
+def test_nested_separator(monkeypatch):
+    argv = sys.argv.copy() + [
+        "--conf_inner__attr1",
+        "1",
+        "--conf_attr2",
+        "2",
+        "--attr1",
+        "100",
+    ]
+    monkeypatch.setattr(sys, "argv", argv)
+    config = OuterConfig(
+        config_sources=ConfZCLArgSource(prefix="conf_", nested_separator="__")
+    )
+    assert config.inner.attr1 == 1
+    assert config.attr2 == 2

tests/loaders/test_env_loader.py

@@ -128,3 +128,15 @@ def test_dotenv_loading(monkeypatch):
     assert config.attr2 == 1
     assert config.inner.attr1_name == 21
     assert config.inner.attr_override == "2002"
+
+
+def test_separator(monkeypatch):
+    monkeypatch.setenv("INNER__ATTR1_NAME", "21")
+    monkeypatch.setenv("INNER__ATTR-OVERRIDE", "2002")
+    monkeypatch.setenv("ATTR2", "1")
+    config = OuterConfig(
+        config_sources=ConfZEnvSource(allow_all=True, nested_separator="__")
+    )
+    assert config.attr2 == 1
+    assert config.inner.attr1_name == 21
+    assert config.inner.attr_override == "2002"