add flatten function

mlconfig/__init__.py

@@ -1,3 +1,4 @@
+from .conf import flatten
 from .conf import getcls
 from .conf import instantiate
 from .conf import load

mlconfig/conf.py

@@ -1,5 +1,6 @@
 import copy
 import functools
+from typing import Optional
 
 from omegaconf import OmegaConf
 
@@ -77,3 +78,19 @@ def instantiate(conf, *args, **kwargs):
     func_or_cls = getcls(conf)
 
     return func_or_cls(*args, **kwargs)
+
+
+def flatten(data: dict, prefix: Optional[str] = None, sep: str = ".") -> dict:
+    d = {}
+
+    for key, value in data.items():
+        if prefix is not None:
+            key = prefix + sep + key
+
+        if isinstance(value, dict):
+            d.update(flatten(value, prefix=key))
+            continue
+
+        d[key] = value
+
+    return d

tests/test_conf.py

@@ -1,5 +1,6 @@
 import pytest
 
+from mlconfig import flatten
 from mlconfig import getcls
 from mlconfig import instantiate
 from mlconfig import load
@@ -55,3 +56,16 @@ def test_instantiate(conf, obj):
 
 def test_getcls(conf):
     assert getcls(conf["a"]) == Point
+
+
+@pytest.mark.parametrize(
+    "test_input,expected",
+    [
+        ({}, {}),
+        ({"a": "b"}, {"a": "b"}),
+        ({"a": {"b": {"c": "d"}}}, {"a.b.c": "d"}),
+        ({"a": {"b": "c"}, "d": {"e": "f"}}, {"a.b": "c", "d.e": "f"}),
+    ],
+)
+def test_flatten(test_input: dict, expected: dict) -> None:
+    assert flatten(test_input) == expected