Switch Plottable to a Protocol

Author: exrhizo

docs/source/api/plotter.rst

@@ -18,13 +18,6 @@ Plotter Class
    :inherited-members:
    :show-inheritance:
 
-Plottable Interface
-----------------------
-.. automodule:: graphistry.Plottable
-   :members:
-   :undoc-members:
-   :inherited-members:
-   :show-inheritance:
 
 PlotterBase Class
 ----------------------

graphistry/Engine.py

@@ -39,7 +39,6 @@ def resolve_engine(
         return Engine(engine.value)
 
     if g_or_df is not None:
-        # work around circular dependency
         from graphistry.Plottable import Plottable
         if isinstance(g_or_df, Plottable):
             if g_or_df._nodes is not None and g_or_df._edges is not None:
@@ -48,7 +47,6 @@ def resolve_engine(
                     warnings.warn(f'Edges and nodes must be same type for auto engine selection, got: {type(g_or_df._edges)} and {type(g_or_df._nodes)}')                
             g_or_df = g_or_df._edges if g_or_df._edges is not None else g_or_df._nodes
 
-    if g_or_df is not None:
         if isinstance(g_or_df, pd.DataFrame):
             return Engine.PANDAS