Switched dag_drawer from pydot to retworkx (#8162)

* switched `dag_drawer` from pydot to `retworkx` * added optional annotation to method * added graphviz annotations to tests * minor fixes * added mapping to `retworkx` Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Qiskit · Jun 15, 2022 · 5f77531 · 5f77531
1 parent 1e872b7
commit 5f77531
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Showing 3 changed files with 26 additions and 106 deletions.
diff --git a/docs/conf.py b/docs/conf.py
@@ -32,6 +32,7 @@
     "sphinx.ext.mathjax",
     "sphinx.ext.viewcode",
     "sphinx.ext.extlinks",
+    "sphinx.ext.intersphinx",
     "jupyter_sphinx",
     "sphinx_autodoc_typehints",
     "reno.sphinxext",
@@ -59,6 +60,9 @@
 # (e.g., if this is set to ['foo.'], then foo.bar is shown under B, not F).
 modindex_common_prefix = ["qiskit."]
 
+intersphinx_mapping = {
+    'retworkx': ('https://qiskit.org/documentation/retworkx/', None),
+}
 
 # -- Options for HTML output -------------------------------------------------
 

diff --git a/qiskit/visualization/dag_visualization.py b/qiskit/visualization/dag_visualization.py
@@ -15,89 +15,22 @@
 """
 Visualization function for DAG circuit representation.
 """
-
-import os
-import sys
-import tempfile
+from retworkx.visualization import graphviz_draw
 
 from qiskit.dagcircuit.dagnode import DAGOpNode, DAGInNode, DAGOutNode
 from qiskit.circuit import Qubit
 from qiskit.utils import optionals as _optionals
 from qiskit.exceptions import InvalidFileError
 from .exceptions import VisualizationError
 
-FILENAME_EXTENSIONS = {
-    "bmp",
-    "canon",
-    "cgimage",
-    "cmap",
-    "cmapx",
-    "cmapx_np",
-    "dot",
-    "dot_json",
-    "eps",
-    "exr",
-    "fig",
-    "gd",
-    "gd2",
-    "gif",
-    "gv",
-    "icns",
-    "ico",
-    "imap",
-    "imap_np",
-    "ismap",
-    "jp2",
-    "jpe",
-    "jpeg",
-    "jpg",
-    "json",
-    "json0",
-    "mp",
-    "pct",
-    "pdf",
-    "pic",
-    "pict",
-    "plain",
-    "plain-ext",
-    "png",
-    "pov",
-    "ps",
-    "ps2",
-    "psd",
-    "sgi",
-    "svg",
-    "svgz",
-    "tga",
-    "tif",
-    "tiff",
-    "tk",
-    "vdx",
-    "vml",
-    "vmlz",
-    "vrml",
-    "wbmp",
-    "webp",
-    "xdot",
-    "xdot1.2",
-    "xdot1.4",
-    "xdot_json",
-}
-
 
-@_optionals.HAS_PYDOT.require_in_call
+@_optionals.HAS_GRAPHVIZ.require_in_call
 def dag_drawer(dag, scale=0.7, filename=None, style="color"):
     """Plot the directed acyclic graph (dag) to represent operation dependencies
     in a quantum circuit.
 
-    Note this function leverages
-    `pydot <https://github.com/erocarrera/pydot>`_ to generate the graph, which
-    means that having `Graphviz <https://www.graphviz.org/>`_ installed on your
-    system is required for this to work.
-
-    The current release of Graphviz can be downloaded here: <https://graphviz.gitlab.io/download/>.
-    Download the version of the software that matches your environment and follow the instructions
-    to install Graph Visualization Software (Graphviz) on your operating system.
+    This function calls the :func:`~retworkx.visualization.graphviz_draw` function from the ``retworkx``
+    package to draw the DAG.
 
     Args:
         dag (DAGCircuit): The dag to draw.
@@ -112,7 +45,6 @@ def dag_drawer(dag, scale=0.7, filename=None, style="color"):
 
     Raises:
         VisualizationError: when style is not recognized.
-        MissingOptionalLibraryError: when pydot or pillow are not installed.
         InvalidFileError: when filename provided is not valid
 
     Example:
@@ -135,7 +67,6 @@ def dag_drawer(dag, scale=0.7, filename=None, style="color"):
             dag = circuit_to_dag(circ)
             dag_drawer(dag)
     """
-    import pydot
 
     # NOTE: use type str checking to avoid potential cyclical import
     # the two tradeoffs ere that it will not handle subclasses and it is
@@ -225,38 +156,16 @@ def edge_attr_func(edge):
             e["label"] = label
             return e
 
-    dot_str = dag._multi_graph.to_dot(node_attr_func, edge_attr_func, graph_attrs)
-    dot = pydot.graph_from_dot_data(dot_str)[0]
-
+    image_type = None
     if filename:
         if "." not in filename:
             raise InvalidFileError("Parameter 'filename' must be in format 'name.extension'")
-        extension = filename.split(".")[-1]
-        if extension not in FILENAME_EXTENSIONS:
-            raise InvalidFileError(
-                "Filename extension must be one of: " + " ".join(FILENAME_EXTENSIONS)
-            )
-        dot.write(filename, format=extension)
-        return None
-    elif ("ipykernel" in sys.modules) and ("spyder" not in sys.modules):
-        _optionals.HAS_PIL.require_now("dag_drawer")
-        from PIL import Image
-
-        with tempfile.TemporaryDirectory() as tmpdirname:
-            tmp_path = os.path.join(tmpdirname, "dag.png")
-            dot.write_png(tmp_path)
-            with Image.open(tmp_path) as test_image:
-                image = test_image.copy()
-            os.remove(tmp_path)
-            return image
-    else:
-        _optionals.HAS_PIL.require_now("dag_drawer")
-        from PIL import Image
-
-        with tempfile.TemporaryDirectory() as tmpdirname:
-            tmp_path = os.path.join(tmpdirname, "dag.png")
-            dot.write_png(tmp_path)
-            image = Image.open(tmp_path)
-            image.show()
-            os.remove(tmp_path)
-            return None
+        image_type = filename.split(".")[-1]
+    return graphviz_draw(
+        dag._multi_graph,
+        node_attr_func,
+        edge_attr_func,
+        graph_attrs,
+        filename,
+        image_type,
+    )
diff --git a/test/python/visualization/test_dag_drawer.py b/test/python/visualization/test_dag_drawer.py
@@ -38,20 +38,27 @@ def setUp(self):
         circuit.cx(qr[0], qr[1])
         self.dag = circuit_to_dag(circuit)
 
+    @unittest.skipUnless(_optionals.HAS_GRAPHVIZ, "Graphviz not installed")
     def test_dag_drawer_invalid_style(self):
         """Test dag draw with invalid style."""
         self.assertRaises(VisualizationError, dag_drawer, self.dag, style="multicolor")
 
+    @unittest.skipUnless(_optionals.HAS_GRAPHVIZ, "Graphviz not installed")
     def test_dag_drawer_checks_filename_correct_format(self):
         """filename must contain name and extension"""
         with self.assertRaisesRegex(
             InvalidFileError, "Parameter 'filename' must be in format 'name.extension'"
         ):
             dag_drawer(self.dag, filename="aaabc")
 
+    @unittest.skipUnless(_optionals.HAS_GRAPHVIZ, "Graphviz not installed")
     def test_dag_drawer_checks_filename_extension(self):
         """filename must have a valid extension"""
-        with self.assertRaisesRegex(InvalidFileError, "Filename extension must be one of: .*"):
+        with self.assertRaisesRegex(
+            ValueError,
+            "The specified value for the image_type argument, 'abc' is not a "
+            "valid choice. It must be one of: .*",
+        ):
             dag_drawer(self.dag, filename="aa.abc")
 
     @unittest.skipUnless(_optionals.HAS_GRAPHVIZ, "Graphviz not installed")