Add from_dict classmethod (#112)

Author: MarcoGorelli

spec/API_specification/dataframe_api/dataframe_object.py

@@ -1,5 +1,5 @@
 from __future__ import annotations
-from typing import Sequence, Union, TYPE_CHECKING, NoReturn
+from typing import Sequence, Union, TYPE_CHECKING, NoReturn, Mapping
 
 if TYPE_CHECKING:
     from .column_object import Column
@@ -11,6 +11,23 @@
 
 
 class DataFrame:
+    @classmethod
+    def from_dict(cls, data: Mapping[str, Column]) -> DataFrame:
+        """
+        Construct DataFrame from map of column names to Columns.
+
+        Parameters
+        ----------
+        data : Mapping[str, Column]
+            Column must be of the corresponding type of the DataFrame.
+            For example, it is only supported to build a ``LibraryXDataFrame`` using
+            ``LibraryXColumn`` instances.
+
+        Returns
+        -------
+        DataFrame
+        """
+
     @property
     def dataframe(self) -> object:
         """