diff --git a/docs/installation_guide.rst b/docs/installation_guide.rst
index efbf52f..21cdc8e 100644
--- a/docs/installation_guide.rst
+++ b/docs/installation_guide.rst
@@ -6,8 +6,8 @@ Dependencies
 
 The following software and modules are required to run dot2tex:
 
-- Python_ 2.7 or 3.x.
-- pyparsing_. Version 1.4.8 or later is recommended.
+- Python_ 3.x.
+- pyparsing_. Version 3.0 or later is required.
 - Graphviz_. A recent version is required.
 - preview_. A LaTeX package for extracting parts of a document. A free-standing part of the `preview-latex`_/`AUCTeX`_ bundle.
 - `PGF/TikZ`_ version 2.0 or later.
diff --git a/dot2tex/pgfformat.py b/dot2tex/pgfformat.py
index 0ded611..0fd598a 100644
--- a/dot2tex/pgfformat.py
+++ b/dot2tex/pgfformat.py
@@ -1,7 +1,7 @@
 import logging
 
-from .base import DotConvBase, parse_drawstring, get_drawobj_lblstyle
-from .utils import smart_float, nsplit, getboolattr, tikzify
+from .base import DotConvBase, get_drawobj_lblstyle, parse_drawstring
+from .utils import getboolattr, nsplit, smart_float, tikzify
 
 log = logging.getLogger("dot2tex")
 
@@ -171,13 +171,16 @@ def __init__(self, options=None):
                 self.template = PGF210_TEMPLATE
             else:
                 self.template = PGF_TEMPLATE
-        self.styles = dict(dashed='dashed', dotted='dotted',
-                           bold='very thick', filled='fill', invis="",
-                           rounded='rounded corners', )
-        self.dashstyles = dict(
-            dashed=r'\pgfsetdash{{3pt}{3pt}}{0pt}',
-            dotted=r'\pgfsetdash{{\pgflinewidth}{2pt}}{0pt}',
-            bold=r'\pgfsetlinewidth{1.2pt}')
+        self.styles = {
+            'dashed': 'dashed', 'dotted': 'dotted',
+            'bold': 'very thick', 'filled': 'fill', 'invis': '',
+            'rounded': 'rounded corners'
+        }
+        self.dashstyles = {
+            'dashed': r'\pgfsetdash{{3pt}{3pt}}{0pt}',
+            'dotted': r'\pgfsetdash{{\pgflinewidth}{2pt}}{0pt}',
+            'bold': r'\pgfsetlinewidth{1.2pt}'
+        }
 
     def start_node(self, node):
         # Todo: Should find a more elegant solution
@@ -267,12 +270,9 @@ def set_color(self, drawop):
         return s
 
     def set_style(self, drawop):
-        c, style = drawop
+        _, style = drawop
         pgfstyle = self.dashstyles.get(style, "")
-        if pgfstyle:
-            return "  %s\n" % pgfstyle
-        else:
-            return ""
+        return f"  {pgfstyle}\n" if pgfstyle else ""
 
     def filter_styles(self, style):
         filtered_styles = []
@@ -299,36 +299,27 @@ def draw_with_opacity(self, pathstr, fill=False):
     def draw_ellipse(self, drawop, style=None):
         op, x, y, w, h = drawop
         should_fill = (op == 'E')
-
-        if style:
-            stylestr = " [%s]" % style
-        else:
-            stylestr = ''
+        stylestr = f" [{style}]" if style else ''
         return self.draw_with_opacity(
-                "%s (%sbp,%sbp) ellipse (%sbp and %sbp)" % (
-                    stylestr, smart_float(x), smart_float(y),
-                    smart_float(w), smart_float(h)),
-                fill=should_fill)
+            "%s (%sbp,%sbp) ellipse (%sbp and %sbp)" % (
+                stylestr, smart_float(x), smart_float(y),
+                smart_float(w), smart_float(h)),
+            fill=should_fill)
 
     def draw_polygon(self, drawop, style=None):
         op, points = drawop
-        pp = ['(%sbp,%sbp)' % (smart_float(p[0]), smart_float(p[1])) for p in points]
-        if op == 'P':
-            should_fill = True
-        else:
-            should_fill = False
-
-        if style:
-            stylestr = " [%s]" % style
-        else:
-            stylestr = ''
+        pp = ['(%sbp,%sbp)' % (smart_float(p0), smart_float(p1))
+              for p0, p1 in points]
+        should_fill = op == 'P'
+        stylestr = f" [{style}]" if style else ''
         return self.draw_with_opacity(
             "%s %s -- cycle" % (stylestr, " -- ".join(pp)),
             fill=should_fill)
 
     def draw_polyline(self, drawop, style=None):
         op, points = drawop
-        pp = ['(%sbp,%sbp)' % (smart_float(p[0]), smart_float(p[1])) for p in points]
+        pp = ['(%sbp,%sbp)' % (smart_float(p[0]), smart_float(p[1]))
+              for p in points]
         stylestr = ''
         return self.draw_with_opacity("%s %s" % (stylestr, " -- ".join(pp)))
 
@@ -350,7 +341,7 @@ def draw_text(self, drawop, style=None):
             alignstr = ""  # centered (default)
         styles.append(alignstr)
         styles.append(style)
-        lblstyle = ",".join([i for i in styles if i])
+        lblstyle = ",".join(i for i in styles if i)
         if lblstyle:
             lblstyle = '[' + lblstyle + ']'
         s = "  \\draw (%sbp,%sbp) node%s {%s};\n" % (smart_float(x), smart_float(y), lblstyle, text)
@@ -448,10 +439,7 @@ def draw_edge(self, edge):
                 # log.warning('label: %s', edgelabel)
 
                 lblstyle = get_drawobj_lblstyle(edge)
-                if lblstyle:
-                    lblstyle = '[' + lblstyle + ']'
-                else:
-                    lblstyle = ''
+                lblstyle = ('[' + lblstyle + ']') if lblstyle else ''
                 if edgelabel:
                     extra = " node%s {%s}" % (lblstyle, edgelabel)
             src = pp[0]
@@ -496,24 +484,21 @@ def get_node_preproc_code(self, node):
         text = node.attr.get('texlbl', '')
         if lblstyle:
             return "  \\tikz \\node[%s] {%s};\n" % (lblstyle, text)
-        else:
-            return r"\tikz \node {" + text + "};"
+        return r"\tikz \node {" + text + "};"
 
     def get_edge_preproc_code(self, edge, attribute="texlbl"):
         lblstyle = edge.attr.get('lblstyle', '')
         text = edge.attr.get(attribute, '')
         if lblstyle:
             return "  \\tikz \\node[%s] {%s};\n" % (lblstyle, text)
-        else:
-            return r"\tikz \node " + "{" + text + "};"
+        return r"\tikz \node " + "{" + text + "};"
 
     def get_graph_preproc_code(self, graph):
         lblstyle = graph.attr.get('lblstyle', '')
         text = graph.attr.get('texlbl', '')
         if lblstyle:
             return "  \\tikz \\node[%s] {%s};\n" % (lblstyle, text)
-        else:
-            return r"\tikz \node {" + text + "};"
+        return r"\tikz \node {" + text + "};"
 
 
 TIKZ_TEMPLATE = r"""\documentclass{standalone}
@@ -699,13 +684,16 @@ def __init__(self, options=None):
             self.template = TIKZ_TEMPLATE
         DotConvBase.__init__(self, options)
 
-        self.styles = dict(dashed='dashed', dotted='dotted',
-                           bold='very thick', filled='fill', invis="", invisible="",
-                           rounded='rounded corners', )
-        self.dashstyles = dict(
-            dashed=r'\pgfsetdash{{3pt}{3pt}}{0pt}',
-            dotted=r'\pgfsetdash{{\pgflinewidth}{2pt}}{0pt}',
-            bold=r'\pgfsetlinewidth{1.2pt}')
+        self.styles = {
+            'dashed': 'dashed', 'dotted': 'dotted',
+            'bold': 'very thick', 'filled': 'fill', 'invis': '',
+            'invisible': '', 'rounded': 'rounded corners'
+        }
+        self.dashstyles = {
+            'dashed': r'\pgfsetdash{{3pt}{3pt}}{0pt}',
+            'dotted': r'\pgfsetdash{{\pgflinewidth}{2pt}}{0pt}',
+            'bold': r'\pgfsetlinewidth{1.2pt}'
+        }
 
     def set_options(self):
         Dot2PGFConv.set_options(self)
@@ -784,10 +772,7 @@ def do_nodes(self):
             if not pos:
                 continue
             x, y = pos.split(',')
-            if dotshape != 'point':
-                label = self.get_label(node)
-            else:
-                label = ''
+            label = '' if dotshape == 'point' else self.get_label(node)
 
             pos = "%sbp,%sbp" % (smart_float(x), smart_float(y))
             style = node.attr.get('style') or ""
@@ -942,10 +927,7 @@ def draw_edge(self, edge):
                 edgelabel = self.get_label(edge)
                 # log.warning('label: %s', edgelabel)
                 lblstyle = get_drawobj_lblstyle(edge, extra_styles=edge.attr.get('exstyle'))
-                if lblstyle:
-                    lblstyle = '[' + lblstyle + ']'
-                else:
-                    lblstyle = ''
+                lblstyle = ('[' + lblstyle + ']') if lblstyle else ''
                 if edgelabel:
                     extra = " node%s {%s}" % (lblstyle, edgelabel)
 
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..55bb56f
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,41 @@
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "dot2tex"
+version = '2.12.0'
+
+description = "A Graphviz to LaTeX converter"
+readme = "readme.md"
+requires-python = ">=3.7"
+dependencies = [
+    "pyparsing >= 3.0",
+]
+authors = [
+  {name = "Kjell Magne Fauske", email = "kjellmf@gmail.com"},
+]
+license = "MIT"
+
+classifiers = [
+  'Development Status :: 4 - Beta',
+  'Environment :: Console',
+  'Intended Audience :: Science/Research',
+  'Natural Language :: English',
+  'Operating System :: OS Independent',
+  'Programming Language :: Python :: 3',
+  'Topic :: Scientific/Engineering :: Visualization',
+  'Topic :: Text Processing :: Markup :: LaTeX',
+  'Topic :: Utilities',
+]
+
+[project.urls]
+"Homepage" = "https://github.com/sagemath/dot2tex"
+
+[project.scripts]
+dot2tex = "dot2tex.dot2tex:main"
+
+[project.optional-dependencies]
+test = [
+    "pytest",
+]
diff --git a/readme.md b/readme.md
index ff64615..0d8d321 100644
--- a/readme.md
+++ b/readme.md
@@ -22,8 +22,7 @@ Before you install dot2tex you have to have a working Python environment
 installed on your system. Dot2tex works with Python 3. In addition
 you will need the following modules:
 
-* [pyparsing](https://github.com/pyparsing/pyparsing). A recent version is required.
-      Older version like for instance 1.3.2 does not work with dot2tex.
+* [pyparsing](https://github.com/pyparsing/pyparsing). A recent version is required, at least version 3.0.
 * [preview](https://ctan.org/pkg/preview)
       A stand-alone part of the preview-latex bundle.
       Required for preprocessing graphs with LaTeX.
diff --git a/setup.py b/setup.py
deleted file mode 100644
index b273f17..0000000
--- a/setup.py
+++ /dev/null
@@ -1,43 +0,0 @@
-#!/usr/bin/env python
-from setuptools import setup
-
-setup(name='dot2tex',
-      version='2.12.0',
-      description='A Graphviz to LaTeX converter',
-      long_description="""\
-The purpose of dot2tex is to give graphs generated by the graph layout tool
-Graphviz_, a more LaTeX friendly look and feel. This is accomplished by:
-
-- Using native PSTricks_ and `PGF/TikZ`_ commands for drawing arrows,
-  edges and nodes.
-- Typesetting labels with LaTeX, allowing mathematical notation.
-- Using backend specific styles to customize the output.
-
-.. _Graphviz: http://www.graphviz.org/
-.. _PSTricks: http://tug.org/PSTricks/main.cgi/
-.. _PGF/TikZ: http://www.ctan.org/tex-archive/help/Catalogue/entries/pgf.html
-""",
-      author='Kjell Magne Fauske',
-      author_email='kjellmf@gmail.com',
-      url="https://github.com/sagemath/dot2tex",
-      packages=['dot2tex'],
-      classifiers=[
-          'Development Status :: 4 - Beta',
-          'Environment :: Console',
-          'Intended Audience :: Science/Research',
-          'License :: OSI Approved :: MIT License',
-          'Natural Language :: English',
-          'Operating System :: OS Independent',
-          'Programming Language :: Python :: 3',
-          'Topic :: Scientific/Engineering :: Visualization',
-          'Topic :: Text Processing :: Markup :: LaTeX',
-          'Topic :: Utilities',
-      ],
-      install_requires=['pyparsing', 'setuptools'],
-      entry_points={
-          'console_scripts': [
-              'dot2tex = dot2tex.dot2tex:main',
-          ]
-
-      }
-)
diff --git a/tests/experimental/test_comparedotparsing.py b/tests/experimental/test_comparedotparsing.py
index ccd188d..b2503a1 100644
--- a/tests/experimental/test_comparedotparsing.py
+++ b/tests/experimental/test_comparedotparsing.py
@@ -127,7 +127,7 @@ def test_subgraphs(self):
     def test_quoting(self):
         self.assertEqual(test_dotfile("quoting.dot"), 1)
 
-    # the following three files are missing, so desactivate
+    # the following three files are missing, so deactivate
 
     # def test_unicode1(self):
     #     self.assertEqual(test_dotfile("unicode1.dot"), 1)
diff --git a/tests/test_dotparsing.py b/tests/test_dotparsing.py
index 1ca52a2..8eaa67e 100644
--- a/tests/test_dotparsing.py
+++ b/tests/test_dotparsing.py
@@ -51,11 +51,10 @@ def test_create_with_attributes(self):
         self.assertEqual(g.attr['style'], 'fancy')
         self.assertEqual(g.attr['label'], 'testgraph')
 
-
     def test_add_node(self):
         g = dotp.DotGraph()
-        na = g.add_node('a')
-        nb = g.add_node('b')
+        _ = g.add_node('a')
+        _ = g.add_node('b')
         self.assertEqual(len(list(g.nodes)), 2)
 
     ##
@@ -79,8 +78,8 @@ def test_add_nonstring_nodes(self):
 
     def test_add_edge(self):
         g = dotp.DotGraph()
-        e = g.add_edge('a', 'b', label='test')
-        e2 = g.add_edge('a', 'd', label='test2')
+        _ = g.add_edge('a', 'b', label='test')
+        _ = g.add_edge('a', 'd', label='test2')
         self.assertEqual(len(g), 3)
         self.assertEqual(len(g.edges), 2)
 
@@ -142,157 +141,153 @@ def test_add_default_node_subgraph(self):
         self.assertFalse('style' in nn.attr)
 
 
-##
-##
-##    def test_addequalnodes2(self):
-##        g = dotp.DotGraph()
-##        n = dotp.DotNode('a',label="test1")
-##        g.add_node(n)
-##        n = dotp.DotNode('a',style="filled")
-##        g.add_node(n)
-##        g.add_node('a',label="test2",texmode="math")
-##        n = g.get_node('a')
-##        self.assertEqual(len(g.nodes),1)
-##        self.assertEqual(len(n.attributes),3)
-##        self.assertEqual(n.attributes['label'],'test2')
-##        self.assertEqual(set(n.attributes.keys()),set(['label','style','texmode']))
-##
-##    def test_getnodes(self):
-##        g = dotp.DotGraph()
-##        n = g.get_node('a')
-##        self.assertEqual(n,None)
-##        g.add_node('a')
-##        n = g.get_node('a')
-##        self.assertEqual(n.name,'a')
-##
-##    def test_addedge(self):
-##        g = dotp.DotGraph(graph_type='digraph')
-##        e1 = g.add_edge('a','b',label='a->b')
-##        e2 = g.add_edge('b','a',label='b->a')
-##        self.assertEqual(len(g.nodes),2)
-##        self.assertEqual(len(g.edges),2)
-##        self.assertEqual(e1.attributes['label'],'a->b')
-##        self.assertEqual(e2.attributes['label'],'b->a')
-##
-##
-##
-##
-##
-##
-##    def test_strictgraph(self):
-##        """A strict graph have to ignore duplicate edges"""
-##        g = dotp.DotGraph(strict=True)
-##        g.add_edge('a','b')
-##        g.add_edge('a','b')
-##        self.assertEqual(len(g.edges),1)
-##
-##    def test_addsubgraphs(self):
-##        g = dotp.DotGraph()
-##        g.add_edge('a','b')
-##        n = g.get_node('a')
-##        self.assertEqual(n.parent,g)
-##        gs = g.add_subgraph('clusterG')
-##        gs.add_edge('a','b')
-##        #n = g.get_node('a')
-##        self.assertEqual(n.parent,gs)
-##        n = g.add_node('a',label="test")
-##
-##        self.assertEqual(n.parent,gs)
-##
-##    def test_graphlevels(self):
-##        g = dotp.DotGraph()
-##        e = g.add_edge('a','b')
-##        self.assertEqual(g.level,0)
-##        gs1 = g.add_subgraph('clusterG')
-##        self.assertEqual(gs1.level,1)
-##        gs2 = g.add_subgraph('clusterGG')
-##        self.assertEqual(gs2.level,1)
-##        gs12 = gs1.add_subgraph('ClusterG2')
-##        self.assertEqual(gs12.level,2)
-##        e = gs12.add_edge('c','d')
-##        self.assertEqual(e.src.parent.level,2)
-##        self.assertEqual(e.parent.level,2)
-##
-##    def test_addedgesubgraphs(self):
-##        """
-##        digraph G {
-##        	a -> b;
-##        	subgraph clusterG {
-##        		a -> b;
-##        	}
-##        	subgraph clusterGG {
-##        		a -> b;
-##        	}
-##
-##strict digraph G {
-##        node [label="\N"];
-##        graph [bb="0,0,86,140"];
-##        subgraph clusterG {
-##                graph [bb="8,8,78,132"];
-##                a [pos="43,106", width="0.75", height="0.50"];
-##                b [pos="43,34", width="0.75", height="0.50"];
-##                a -> b [pos="e,43,52 43,88 43,80 43,71 43,62"];
-##        }
-##}
-##        }"""
-##        g = dotp.DotGraph()
-##        e1 = g.add_edge('a','b')
-##        self.assertEqual(e1.parent.name,g.name)
-##        gs = g.add_subgraph('clusterG')
-##        e2 = gs.add_edge('a','b')
-##        self.assertEqual(e2.parent.name,gs.name)
-##        self.assertEqual(e1.parent.name,gs.name)
-##        gs2 = g.add_subgraph('clusterGG')
-##        e3 = gs2.add_edge('a','b')
-##        self.assertEqual(e2.parent.name,gs.name)
-##        self.assertEqual(e3.parent.name,gs.name)
-##        self.assertEqual(len(gs2.edges),3)
-##
-##    def test_add_single_edge_to_subgraph(self):
-##        """Edge should belong to subgraph"""
-##        g = dotp.DotGraph()
-##        gs = g.add_subgraph('clusterG')
-##        na = gs.add_node('a')
-##        nb = gs.add_node('b')
-##        edge = g.add_edge('a','b')
-##        self.assertEqual(na.parent,gs)
-##        self.assertEqual(nb.parent,gs)
-##        self.assertEqual(edge.parent.name,gs.name)
-##
-##    def test_add_multiple_edges_to_subgraph(self):
-##        """Edges should belong to subgraph"""
-##        g = dotp.DotGraph()
-##        gs = g.add_subgraph('clusterG')
-##        na = gs.add_node('a')
-##        nb = gs.add_node('b')
-##        edge = g.add_edge('a','b')
-##        self.assertEqual(edge.parent.name,gs.name)
-##        edge2 = g.add_edge('a','b')
-##        self.assertEqual(edge2.parent.name,gs.name)
-##
-##    def test_change_edge_parent(self):
-##        """If edge nodes change parents, so should the edge"""
-##        g = dotp.DotGraph()
-##        edge = g.add_edge('a','b')
-##        gs = g.add_subgraph('clusterG')
-##        na = gs.add_node('a')
-##        nb = gs.add_node('b')
-##        self.assertEqual(edge.parent.name,gs.name)
-##
-##
-##
-##
-##
-##
-##
-##
-##
-##
-##
-
-
-
-
+#
+#
+#    def test_addequalnodes2(self):
+#        g = dotp.DotGraph()
+#        n = dotp.DotNode('a',label="test1")
+#        g.add_node(n)
+#        n = dotp.DotNode('a',style="filled")
+#        g.add_node(n)
+#        g.add_node('a',label="test2",texmode="math")
+#        n = g.get_node('a')
+#        self.assertEqual(len(g.nodes),1)
+#        self.assertEqual(len(n.attributes),3)
+#        self.assertEqual(n.attributes['label'],'test2')
+#        self.assertEqual(set(n.attributes.keys()),set(['label','style','texmode']))
+#
+#    def test_getnodes(self):
+#        g = dotp.DotGraph()
+#        n = g.get_node('a')
+#        self.assertEqual(n,None)
+#        g.add_node('a')
+#        n = g.get_node('a')
+#        self.assertEqual(n.name,'a')
+#
+#    def test_addedge(self):
+#        g = dotp.DotGraph(graph_type='digraph')
+#        e1 = g.add_edge('a','b',label='a->b')
+#        e2 = g.add_edge('b','a',label='b->a')
+#        self.assertEqual(len(g.nodes),2)
+#        self.assertEqual(len(g.edges),2)
+#        self.assertEqual(e1.attributes['label'],'a->b')
+#        self.assertEqual(e2.attributes['label'],'b->a')
+#
+#
+#
+#
+#
+#
+#    def test_strictgraph(self):
+#        """A strict graph have to ignore duplicate edges"""
+#        g = dotp.DotGraph(strict=True)
+#        g.add_edge('a','b')
+#        g.add_edge('a','b')
+#        self.assertEqual(len(g.edges),1)
+#
+#    def test_addsubgraphs(self):
+#        g = dotp.DotGraph()
+#        g.add_edge('a','b')
+#        n = g.get_node('a')
+#        self.assertEqual(n.parent,g)
+#        gs = g.add_subgraph('clusterG')
+#        gs.add_edge('a','b')
+#        #n = g.get_node('a')
+#        self.assertEqual(n.parent,gs)
+#        n = g.add_node('a',label="test")
+#
+#        self.assertEqual(n.parent,gs)
+#
+#    def test_graphlevels(self):
+#        g = dotp.DotGraph()
+#        e = g.add_edge('a','b')
+#        self.assertEqual(g.level,0)
+#        gs1 = g.add_subgraph('clusterG')
+#        self.assertEqual(gs1.level,1)
+#        gs2 = g.add_subgraph('clusterGG')
+#        self.assertEqual(gs2.level,1)
+#        gs12 = gs1.add_subgraph('ClusterG2')
+#        self.assertEqual(gs12.level,2)
+#        e = gs12.add_edge('c','d')
+#        self.assertEqual(e.src.parent.level,2)
+#        self.assertEqual(e.parent.level,2)
+#
+#    def test_addedgesubgraphs(self):
+#        """
+#        digraph G {
+#        	a -> b;
+#        	subgraph clusterG {
+#        		a -> b;
+#        	}
+#        	subgraph clusterGG {
+#        		a -> b;
+#        	}
+#
+# strict digraph G {
+#        node [label="\N"];
+#        graph [bb="0,0,86,140"];
+#        subgraph clusterG {
+#                graph [bb="8,8,78,132"];
+#                a [pos="43,106", width="0.75", height="0.50"];
+#                b [pos="43,34", width="0.75", height="0.50"];
+#                a -> b [pos="e,43,52 43,88 43,80 43,71 43,62"];
+#        }
+# }
+#        }"""
+#        g = dotp.DotGraph()
+#        e1 = g.add_edge('a','b')
+#        self.assertEqual(e1.parent.name,g.name)
+#        gs = g.add_subgraph('clusterG')
+#        e2 = gs.add_edge('a','b')
+#        self.assertEqual(e2.parent.name,gs.name)
+#        self.assertEqual(e1.parent.name,gs.name)
+#        gs2 = g.add_subgraph('clusterGG')
+#        e3 = gs2.add_edge('a','b')
+#        self.assertEqual(e2.parent.name,gs.name)
+#        self.assertEqual(e3.parent.name,gs.name)
+#        self.assertEqual(len(gs2.edges),3)
+#
+#    def test_add_single_edge_to_subgraph(self):
+#        """Edge should belong to subgraph"""
+#        g = dotp.DotGraph()
+#        gs = g.add_subgraph('clusterG')
+#        na = gs.add_node('a')
+#        nb = gs.add_node('b')
+#        edge = g.add_edge('a','b')
+#        self.assertEqual(na.parent,gs)
+#        self.assertEqual(nb.parent,gs)
+#        self.assertEqual(edge.parent.name,gs.name)
+#
+#    def test_add_multiple_edges_to_subgraph(self):
+#        """Edges should belong to subgraph"""
+#        g = dotp.DotGraph()
+#        gs = g.add_subgraph('clusterG')
+#        na = gs.add_node('a')
+#        nb = gs.add_node('b')
+#        edge = g.add_edge('a','b')
+#        self.assertEqual(edge.parent.name,gs.name)
+#        edge2 = g.add_edge('a','b')
+#        self.assertEqual(edge2.parent.name,gs.name)
+#
+#    def test_change_edge_parent(self):
+#        """If edge nodes change parents, so should the edge"""
+#        g = dotp.DotGraph()
+#        edge = g.add_edge('a','b')
+#        gs = g.add_subgraph('clusterG')
+#        na = gs.add_node('a')
+#        nb = gs.add_node('b')
+#        self.assertEqual(edge.parent.name,gs.name)
+#
+#
+#
+#
+#
+#
+#
+#
+#
+#
+#
 
 
 if __name__ == '__main__':