type DataFrame, Column, and GroupBy as Protocol (#291)

Author: MarcoGorelli

spec/API_specification/.mypy.ini

@@ -1,5 +1,2 @@
 [mypy]
 strict=True
-
-[mypy-dataframe_api.*]
-disable_error_code=empty-body

spec/API_specification/dataframe_api/__init__.py

@@ -1,3 +1,4 @@
+# mypy: disable-error-code="empty-body"
 """
 Function stubs and API documentation for the DataFrame API standard.
 """

spec/API_specification/dataframe_api/column_object.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Any,NoReturn, TYPE_CHECKING, Literal, Generic
+from typing import Any,NoReturn, TYPE_CHECKING, Literal, Protocol
 
 if TYPE_CHECKING:
     from .typing import NullType, Scalar, DType, Namespace
@@ -10,7 +10,7 @@
 __all__ = ['Column']
 
 
-class Column:
+class Column(Protocol):
     """
     Column object
 

spec/API_specification/dataframe_api/dataframe_object.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Any, Literal, Mapping, Sequence, Union, TYPE_CHECKING, NoReturn
+from typing import Any, Literal, Mapping, Sequence, TYPE_CHECKING, NoReturn, Protocol
 
 
 if TYPE_CHECKING:
@@ -13,7 +13,7 @@
 __all__ = ["DataFrame"]
 
 
-class DataFrame:
+class DataFrame(Protocol):
     """
     DataFrame object
 

spec/API_specification/dataframe_api/groupby_object.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Protocol
 
 if TYPE_CHECKING:
     from .dataframe_object import DataFrame
@@ -9,7 +9,7 @@
 __all__ = ['GroupBy']
 
 
-class GroupBy:
+class GroupBy(Protocol):
     """
     GroupBy object.