Finish dealing with operators on dataframes

Author: rgommers

spec/API_specification/dataframe_api/dataframe_object.py

@@ -12,14 +12,25 @@
 
 class DataFrame:
     """
-    A DataFrame.
+    DataFrame object
 
-    Notes
-    -----
-    Note that this DataFrame class is not meant to be instantiated directly by
+    Note that this DataFrame object is not meant to be instantiated directly by
     users of the library implementing the dataframe API standard. Rather, use
     constructor functions or an already-created dataframe object retrieved via
     
+    **Python operator support**
+
+    All arithmetic operators defined by the Python language, except for
+    ``__matmul__``, ``__neg__`` and ``__pos__``, must be supported for
+    numerical data types.
+
+    All comparison operators defined by the Python language must be supported
+    by the dataframe object for all data types for which those comparisons are
+    supported by the builtin scalar types corresponding to a data type.
+
+    In-place operators must not be supported. All operations on the dataframe
+    object are out-of-place.
+
     """
     @property
     def dataframe(self) -> object:

spec/API_specification/dataframe_object.rst

@@ -4,57 +4,8 @@ Dataframe object
 ================
 
 A conforming implementation of the dataframe API standard must provide and
-support a dataframe object having the following attributes and methods.
-
-Operators
----------
-
-A conforming implementation of the dataframe API standard must provide and
-support a dataframe object supporting the following Python operators.
-
-Arithmetic Operators
-~~~~~~~~~~~~~~~~~~~~
-
-A conforming implementation of the array API standard must provide and support
-a dataframe object supporting the following Python arithmetic operators.
-
-Arithmetic operators should be defined for a dataframe having real-valued data types.
-
-.. note::
-
-   TODO: figure out whether we want to add ``__neg__`` and ``__pos__``, those
-   are the two missing arithmetic operators.
-
-
-Comparison Operators
-~~~~~~~~~~~~~~~~~~~~
-
-A conforming implementation of the dataframe API standard must provide and
-support a dataframe object supporting the following Python comparison
-operators.
-
-Comparison operators should be defined for dataframes having any data type.
-
-In-place Operators
-~~~~~~~~~~~~~~~~~~
-
-TODO
-
-Reflected Operators
-~~~~~~~~~~~~~~~~~~~
-
-TODO
-
-Arithmetic Operators
-""""""""""""""""""""
-
--   ``__radd__``
--   ``__rsub__``
--   ``__rmul__``
--   ``__rtruediv__``
--   ``__rfloordiv__``
--   ``__rpow__``
--   ``__rmod__``
+support a dataframe object having the following methods, attributes, and
+behavior.
 
 .. currentmodule:: dataframe_api
 

spec/API_specification/groupby_object.rst

@@ -4,9 +4,10 @@ Groupby object
 ==============
 
 A conforming implementation of the dataframe API standard must provide and
-support a groupby object having the following methods.
+support a groupby object with the following API:
 
 .. currentmodule:: dataframe_api
 
 .. autoclass:: GroupBy
 
+