Create builtin-functions in System namespace

Author: rocky

pymathics/graph/__init__.py

@@ -117,6 +117,73 @@
     "requires": ["networkx"],
 }
 
+_BUILTINS_ = (
+    "AcyclicGraphQ",
+    "AdjacencyList",
+    "BalancedTree",
+    "BarbellGraph",
+    "BetweennessCentrality",
+    "BinomialTree",
+    "ClosenessCentrality",
+    "CompleteGraph",
+    "CompleteKaryTree",
+    "ConnectedComponents",
+    "ConnectedGraphQ",
+    "CycleGraph",
+    "DegreeCentrality",
+    "DirectedEdge",
+    "DirectedGraphQ",
+    "EdgeConnectivity",
+    "EdgeCount",
+    "EdgeDelete",
+    "EdgeIndex",
+    "EdgeList",
+    "EdgeRules",
+    "EigenvectorCentrality",
+    "FindShortestPath",
+    "FindSpanningTree",
+    "FindVertexCut",
+    "Graph",
+    "GraphAtlas",
+    "GraphAtom",
+    "GraphBox",
+    "GraphData",
+    "GraphDistance",
+    "GraphQ",
+    "HITSCentrality",
+    "HighlightGraph",
+    "HknHararyGraph",
+    "HmnHararyGraph",
+    "KaryTree",
+    "KatzCentrality",
+    "LadderGraph",
+    "LoopFreeGraphQ",
+    "MixedGraphQ",
+    "MultigraphQ",
+    "PageRankCentrality",
+    "PathGraph",
+    "PathGraphQ",
+    "PlanarGraphQ",
+    "Property",
+    "PropertyValue",
+    "RandomGraph",
+    "RandomTree",
+    "SimpleGraphQ",
+    "StarGraph",
+    "TreeGraph",
+    "TreeGraphAtom",
+    "TreeGraphQ",
+    "UndirectedEdge",
+    "VertexAdd",
+    "VertexConnectivity",
+    "VertexCount",
+    "VertexDegree",
+    "VertexDelete",
+    "VertexIndex",
+    "VertexList",
+    "WeaklyConnectedComponents",
+)
+
 # These are the publicly exported names
 __all__ = [
     "AcyclicGraphQ",

pymathics/graph/boxes.py

@@ -10,7 +10,7 @@
 import tempfile
 from typing import Tuple
 
-from mathics.core.element import BaseElement, BoxElementMixin
+from mathics.core.element import BoxElementMixin
 
 from pymathics.graph.format import png_format_graph, svg_format_graph