ADD: Add mypy.ini to Python client

Author: cjdsellers

databento/common/metadata.py

@@ -25,7 +25,7 @@ def decode_to_json(raw_metadata: bytes) -> Dict[str, Any]:
 
         """
 
-        def enum_value(fn: Callable) -> Any:
+        def enum_value(fn: Callable[[Any], Any]) -> Any:
             return lambda x: fn(x).value
 
         metadata = decode_metadata(raw_metadata)

mypy.ini

@@ -0,0 +1,12 @@
+[mypy]
+python_version = 3.7
+disallow_untyped_defs = true 
+disallow_any_generics = true
+disallow_subclassing_any = true
+ignore_missing_imports = true
+namespace_packages = true
+no_strict_optional = true
+warn_no_return = true
+warn_unused_configs = true
+warn_unused_ignores = true
+

requirements_dev.txt

@@ -1,2 +1,4 @@
 pytest>=7.1.2
 pytest-mock>=3.8.1
+types-requests
+