Move the snake case functions into their own module (#1198)

* Move the snake case functions into their own module

* Address flake8

* Address pydocstyle

* Address black

* Update __init__.py

* Update __init__.py

* Update __init__.py

praw/util/__init__.py

@@ -1,21 +1,4 @@
 """Package imports for utilities."""
 
-import re
-
-__all__ = ("cache", "camel_to_snake", "snake_case_keys")
-
-_re_camel_to_snake = re.compile(r"([a-z0-9](?=[A-Z])|[A-Z](?=[A-Z][a-z]))")
-
-
-def camel_to_snake(name):
-    """Convert `name` from camelCase to snake_case."""
-    return _re_camel_to_snake.sub(r"\1_", name).lower()
-
-
-def snake_case_keys(dictionary):
-    """Return a new dictionary with keys converted to snake_case.
-
-    :param dictionary: The dict to be corrected.
-
-    """
-    return {camel_to_snake(k): v for k, v in dictionary.items()}
+from .cache import cachedproperty  # noqa: F401
+from .snake import camel_to_snake, snake_case_keys  # noqa: F401

praw/util/snake.py

@@ -0,0 +1,19 @@
+"""Contains functions dealing with snake case conversions."""
+
+import re
+
+_re_camel_to_snake = re.compile(r"([a-z0-9](?=[A-Z])|[A-Z](?=[A-Z][a-z]))")
+
+
+def camel_to_snake(name):
+    """Convert `name` from camelCase to snake_case."""
+    return _re_camel_to_snake.sub(r"\1_", name).lower()
+
+
+def snake_case_keys(dictionary):
+    """Return a new dictionary with keys converted to snake_case.
+
+    :param dictionary: The dict to be corrected.
+
+    """
+    return {camel_to_snake(k): v for k, v in dictionary.items()}