Merge pull request #14725 from anntzer/graphviz_dump_transform

QuLogic · web-flow · commit 61435658c4f8 · 2020-03-24T16:01:31.000-04:00
Move the debug-mode TransformNode.write_graphviz out.
diff --git a/lib/matplotlib/_internal_utils.py b/lib/matplotlib/_internal_utils.py
@@ -0,0 +1,64 @@
+"""
+Internal debugging utilities, that are not expected to be used in the rest of
+the codebase.
+
+WARNING: Code in this module may change without prior notice!
+"""
+
+from io import StringIO
+from pathlib import Path
+import subprocess
+
+from matplotlib.transforms import TransformNode
+
+
+def graphviz_dump_transform(transform, dest, *, highlight=None):
+    """
+    Generate a graphical representation of the transform tree for *transform*
+    using the :program:`dot` program (which this function depends on).  The
+    output format (png, dot, etc.) is determined from the suffix of *dest*.
+
+    Parameters
+    ----------
+    transform : `~matplotlib.transform.Transform`
+        The represented transform.
+    dest : str
+        Output filename.  The extension must be one of the formats supported
+        by :program:`dot`, e.g. png, svg, dot, ...
+        (see https://www.graphviz.org/doc/info/output.html).
+    highlight : list of `~matplotlib.transform.Transform` or None
+        The transforms in the tree to be drawn in bold.
+        If *None*, *transform* is highlighted.
+    """
+
+    if highlight is None:
+        highlight = [transform]
+    seen = set()
+
+    def recurse(root, buf):
+        if id(root) in seen:
+            return
+        seen.add(id(root))
+        props = {}
+        label = type(root).__name__
+        if root._invalid:
+            label = f'[{label}]'
+        if root in highlight:
+            props['style'] = 'bold'
+        props['shape'] = 'box'
+        props['label'] = '"%s"' % label
+        props = ' '.join(map('{0[0]}={0[1]}'.format, props.items()))
+        buf.write(f'{id(root)} [{props}];\n')
+        for key, val in vars(root).items():
+            if isinstance(val, TransformNode) and id(root) in val._parents:
+                buf.write(f'"{id(root)}" -> "{id(val)}" '
+                          f'[label="{key}", fontsize=10];\n')
+                recurse(val, buf)
+
+    buf = StringIO()
+    buf.write('digraph G {\n')
+    recurse(transform, buf)
+    buf.write('}\n')
+    subprocess.run(
+        ['dot', '-T', Path(dest).suffix[1:], '-o', dest],
+        input=buf.getvalue().encode('utf-8'), check=True)
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
@@ -200,14 +200,6 @@ def set_children(self, *children):
                 self, lambda _, pop=child._parents.pop, k=id(self): pop(k))
             child._parents[id(self)] = ref
 
-    if DEBUG:
-        _set_children = set_children
-
-        def set_children(self, *children):
-            self._set_children(*children)
-            self._children = children
-        set_children.__doc__ = _set_children.__doc__
-
     def frozen(self):
         """
         Returns a frozen copy of this transform node.  The frozen copy
@@ -217,56 +209,6 @@ def frozen(self):
         """
         return self
 
-    if DEBUG:
-        def write_graphviz(self, fobj, highlight=[]):
-            """
-            For debugging purposes.
-
-            Writes the transform tree rooted at 'self' to a graphviz "dot"
-            format file.  This file can be run through the "dot" utility
-            to produce a graph of the transform tree.
-
-            Affine transforms are marked in blue.  Bounding boxes are
-            marked in yellow.
-
-            *fobj*: A Python file-like object
-
-            Once the "dot" file has been created, it can be turned into a
-            png easily with::
-
-                $> dot -Tpng -o $OUTPUT_FILE $DOT_FILE
-
-            """
-            seen = set()
-
-            def recurse(root):
-                if root in seen:
-                    return
-                seen.add(root)
-                props = {}
-                label = root.__class__.__name__
-                if root._invalid:
-                    label = '[%s]' % label
-                if root in highlight:
-                    props['style'] = 'bold'
-                props['shape'] = 'box'
-                props['label'] = '"%s"' % label
-                props = ' '.join(map('{0[0]}={0[1]}'.format, props.items()))
-
-                fobj.write('%s [%s];\n' % (hash(root), props))
-
-                if hasattr(root, '_children'):
-                    for child in root._children:
-                        name = next((key for key, val in root.__dict__.items()
-                                     if val is child), '?')
-                        fobj.write('"%s" -> "%s" [label="%s", fontsize=10];\n'
-                                   % (hash(root), hash(child), name))
-                        recurse(child)
-
-            fobj.write("digraph G {\n")
-            recurse(self)
-            fobj.write("}\n")
-
 
 class BboxBase(TransformNode):
     """
