Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/networkx/drawing/tests/test_pydot.py

@@ -0,0 +1,94 @@
+"""Unit tests for pydot drawing functions."""
+from io import StringIO
+import tempfile
+import networkx as nx
+from networkx.testing import assert_graphs_equal
+
+import pytest
+
+pydot = pytest.importorskip("pydot")
+
+
+class TestPydot:
+    def pydot_checks(self, G, prog):
+        """
+        Validate :mod:`pydot`-based usage of the passed NetworkX graph with the
+        passed basename of an external GraphViz command (e.g., `dot`, `neato`).
+        """
+
+        # Set the name of this graph to... "G". Failing to do so will
+        # subsequently trip an assertion expecting this name.
+        G.graph["name"] = "G"
+
+        # Add arbitrary nodes and edges to the passed empty graph.
+        G.add_edges_from([("A", "B"), ("A", "C"), ("B", "C"), ("A", "D")])
+        G.add_node("E")
+
+        # Validate layout of this graph with the passed GraphViz command.
+        graph_layout = nx.nx_pydot.pydot_layout(G, prog=prog)
+        assert isinstance(graph_layout, dict)
+
+        # Convert this graph into a "pydot.Dot" instance.
+        P = nx.nx_pydot.to_pydot(G)
+
+        # Convert this "pydot.Dot" instance back into a graph of the same type.
+        G2 = G.__class__(nx.nx_pydot.from_pydot(P))
+
+        # Validate the original and resulting graphs to be the same.
+        assert_graphs_equal(G, G2)
+
+        # Serialize this "pydot.Dot" instance to a temporary file in dot format
+        fname = tempfile.mktemp()
+        P.write_raw(fname)
+
+        # Deserialize a list of new "pydot.Dot" instances back from this file.
+        Pin_list = pydot.graph_from_dot_file(path=fname, encoding="utf-8")
+
+        # Validate this file to contain only one graph.
+        assert len(Pin_list) == 1
+
+        # The single "pydot.Dot" instance deserialized from this file.
+        Pin = Pin_list[0]
+
+        # Sorted list of all nodes in the original "pydot.Dot" instance.
+        n1 = sorted([p.get_name() for p in P.get_node_list()])
+
+        # Sorted list of all nodes in the deserialized "pydot.Dot" instance.
+        n2 = sorted([p.get_name() for p in Pin.get_node_list()])
+
+        # Validate these instances to contain the same nodes.
+        assert n1 == n2
+
+        # Sorted list of all edges in the original "pydot.Dot" instance.
+        e1 = sorted([(e.get_source(), e.get_destination()) for e in P.get_edge_list()])
+
+        # Sorted list of all edges in the original "pydot.Dot" instance.
+        e2 = sorted(
+            [(e.get_source(), e.get_destination()) for e in Pin.get_edge_list()]
+        )
+
+        # Validate these instances to contain the same edges.
+        assert e1 == e2
+
+        # Deserialize a new graph of the same type back from this file.
+        Hin = nx.nx_pydot.read_dot(fname)
+        Hin = G.__class__(Hin)
+
+        # Validate the original and resulting graphs to be the same.
+        assert_graphs_equal(G, Hin)
+
+    def test_undirected(self):
+        self.pydot_checks(nx.Graph(), prog="neato")
+
+    def test_directed(self):
+        self.pydot_checks(nx.DiGraph(), prog="dot")
+
+    def test_read_write(self):
+        G = nx.MultiGraph()
+        G.graph["name"] = "G"
+        G.add_edge("1", "2", key="0")  # read assumes strings
+        fh = StringIO()
+        nx.nx_pydot.write_dot(G, fh)
+        fh.seek(0)
+        H = nx.nx_pydot.read_dot(fh)
+        assert_graphs_equal(G, H)