diff --git a/.style.yapf b/.style.yapf
new file mode 100644
index 00000000..2ef2b908
--- /dev/null
+++ b/.style.yapf
@@ -0,0 +1,4 @@
+[style]
+based_on_style=facebook
+blank_line_before_nested_class_or_def=True
+column_limit=79
diff --git a/dot_parser.py b/dot_parser.py
index e9bc2538..14bfbd05 100644
--- a/dot_parser.py
+++ b/dot_parser.py
@@ -12,24 +12,9 @@
 import sys
 
 from pyparsing import (
-    nestedExpr,
-    Literal,
-    CaselessLiteral,
-    Word,
-    OneOrMore,
-    Forward,
-    Group,
-    Optional,
-    Combine,
-    restOfLine,
-    cStyleComment,
-    nums,
-    alphanums,
-    printables,
-    ParseException,
-    ParseResults,
-    CharsNotIn,
-    QuotedString,
+    nestedExpr, Literal, CaselessLiteral, Word, OneOrMore, Forward, Group,
+    Optional, Combine, restOfLine, cStyleComment, nums, alphanums, printables,
+    ParseException, ParseResults, CharsNotIn, QuotedString
 )
 
 import pydot
@@ -37,7 +22,6 @@
 __author__ = ['Michael Krause', 'Ero Carrera']
 __license__ = 'MIT'
 
-
 PY3 = sys.version_info >= (3, 0, 0)
 if PY3:
     str_type = str
@@ -46,6 +30,7 @@
 
 
 class P_AttrList(object):
+
     def __init__(self, toks):
         self.attrs = {}
         i = 0
@@ -66,15 +51,14 @@ def __repr__(self):
 
 
 class DefaultStatement(P_AttrList):
+
     def __init__(self, default_type, attrs):
         self.default_type = default_type
         self.attrs = attrs
 
     def __repr__(self):
         return "%s(%s, %r)" % (
-            self.__class__.__name__,
-            self.default_type,
-            self.attrs,
+            self.__class__.__name__, self.default_type, self.attrs
         )
 
 
@@ -88,9 +72,8 @@ def push_top_graph_stmt(str, loc, toks):
     for element in toks:
 
         if (
-            isinstance(element, (ParseResults, tuple, list))
-            and len(element) == 1
-            and isinstance(element[0], str_type)
+            isinstance(element, (ParseResults, tuple, list)) and
+            len(element) == 1 and isinstance(element[0], str_type)
         ):
 
             element = element[0]
@@ -143,7 +126,7 @@ def update_parent_graph_hierarchy(g, parent_graph=None, level=0):
     if parent_graph is None:
         parent_graph = g
 
-    for key_name in ('edges',):
+    for key_name in ('edges', ):
 
         if isinstance(g, pydot.frozendict):
             item_dict = g
@@ -156,8 +139,8 @@ def update_parent_graph_hierarchy(g, parent_graph=None, level=0):
         for key, objs in item_dict[key_name].items():
             for obj in objs:
                 if (
-                    'parent_graph' in obj
-                    and obj['parent_graph'].get_parent_graph() == g
+                    'parent_graph' in obj and
+                    obj['parent_graph'].get_parent_graph() == g
                 ):
                     if obj['parent_graph'] is g:
                         pass
@@ -168,7 +151,7 @@ def update_parent_graph_hierarchy(g, parent_graph=None, level=0):
                     for idx, vertex in enumerate(obj['points']):
                         if isinstance(
                             vertex,
-                            (pydot.Graph, pydot.Subgraph, pydot.Cluster),
+                            (pydot.Graph, pydot.Subgraph, pydot.Cluster)
                         ):
                             vertex.set_parent_graph(parent_graph)
                         if isinstance(vertex, pydot.frozendict):
@@ -334,12 +317,9 @@ def push_edge_stmt(str, loc, toks):
 
     if isinstance(toks[2][0], ParseResults):
 
-        n_next_list = [
-            [
-                n.get_name(),
-            ]
-            for n in toks[2][0]
-        ]
+        n_next_list = [[
+            n.get_name(),
+        ] for n in toks[2][0]]
         for n_next in [n for n in n_next_list]:
             n_next_port = do_node_ports(n_next)
             e.append(pydot.Edge(n_prev, n_next[0] + n_next_port, **attrs))
@@ -366,8 +346,9 @@ def push_edge_stmt(str, loc, toks):
 
         for n_next in [n for n in tuple(toks)[2::2]]:
 
-            if isinstance(n_next, P_AttrList) or not isinstance(
-                n_next[0], str_type
+            if (
+                isinstance(n_next, P_AttrList) or
+                not isinstance(n_next[0], str_type)
             ):
                 continue
 
@@ -448,35 +429,32 @@ def parse_html(s, loc, toks):
 
         opener = '<'
         closer = '>'
-        html_text = (
-            nestedExpr(opener, closer, (CharsNotIn(opener + closer)))
-            .setParseAction(parse_html)
-            .leaveWhitespace()
-        )
+        html_text = nestedExpr(opener, closer,
+                               (CharsNotIn(opener + closer)
+                               )).setParseAction(parse_html).leaveWhitespace()
 
-        ID = (
-            identifier | html_text | double_quoted_string | alphastring_
-        ).setName("ID")
+        ID = (identifier | html_text | double_quoted_string |
+              alphastring_).setName("ID")
 
-        float_number = Combine(
-            Optional(minus) + OneOrMore(Word(nums + "."))
-        ).setName("float_number")
+        float_number = Combine(Optional(minus) +
+                               OneOrMore(Word(nums +
+                                              "."))).setName("float_number")
 
         righthand_id = (float_number | ID).setName("righthand_id")
 
         port_angle = (at + ID).setName("port_angle")
 
         port_location = (
-            OneOrMore(Group(colon + ID))
-            | Group(colon + lparen + ID + comma + ID + rparen)
+            OneOrMore(Group(colon + ID)) |
+            Group(colon + lparen + ID + comma + ID + rparen)
         ).setName("port_location")
 
         port = (
-            Group(port_location + Optional(port_angle))
-            | Group(port_angle + Optional(port_location))
+            Group(port_location + Optional(port_angle)) |
+            Group(port_angle + Optional(port_location))
         ).setName("port")
 
-        node_id = ID + Optional(port)
+        node_id = (ID + Optional(port))
         a_list = OneOrMore(
             ID + Optional(equals + righthand_id) + Optional(comma.suppress())
         ).setName("a_list")
@@ -485,18 +463,15 @@ def parse_html(s, loc, toks):
             lbrack.suppress() + Optional(a_list) + rbrack.suppress()
         ).setName("attr_list")
 
-        attr_stmt = (Group(graph_ | node_ | edge_) + attr_list).setName(
-            "attr_stmt"
-        )
+        attr_stmt = (Group(graph_ | node_ | edge_) +
+                     attr_list).setName("attr_stmt")
 
         edgeop = (Literal("--") | Literal("->")).setName("edgeop")
 
         stmt_list = Forward()
         graph_stmt = Group(
-            lbrace.suppress()
-            + Optional(stmt_list)
-            + rbrace.suppress()
-            + Optional(semi.suppress())
+            lbrace.suppress() + Optional(stmt_list) + rbrace.suppress() +
+            Optional(semi.suppress())
         ).setName("graph_stmt")
 
         edge_point = Forward()
@@ -504,13 +479,11 @@ def parse_html(s, loc, toks):
         edgeRHS = OneOrMore(edgeop + edge_point)
         edge_stmt = edge_point + edgeRHS + Optional(attr_list)
 
-        subgraph = Group(subgraph_ + Optional(ID) + graph_stmt).setName(
-            "subgraph"
-        )
+        subgraph = Group(subgraph_ + Optional(ID) +
+                         graph_stmt).setName("subgraph")
 
-        edge_point << Group(subgraph | graph_stmt | node_id).setName(
-            'edge_point'
-        )
+        edge_point << Group(subgraph | graph_stmt |
+                            node_id).setName('edge_point')
 
         node_stmt = (
             node_id + Optional(attr_list) + Optional(semi.suppress())
@@ -518,21 +491,15 @@ def parse_html(s, loc, toks):
 
         assignment = (ID + equals + righthand_id).setName("assignment")
         stmt = (
-            assignment
-            | edge_stmt
-            | attr_stmt
-            | subgraph
-            | graph_stmt
-            | node_stmt
+            assignment | edge_stmt | attr_stmt | subgraph | graph_stmt |
+            node_stmt
         ).setName("stmt")
         stmt_list << OneOrMore(stmt + Optional(semi.suppress()))
 
         graphparser = OneOrMore(
             (
-                Optional(strict_)
-                + Group((graph_ | digraph_))
-                + Optional(ID)
-                + graph_stmt
+                Optional(strict_) + Group((graph_ | digraph_)) + Optional(ID) +
+                graph_stmt
             ).setResultsName("graph")
         )
 
diff --git a/pydot.py b/pydot.py
index 89ff3de7..294d6a7e 100644
--- a/pydot.py
+++ b/pydot.py
@@ -20,248 +20,62 @@
         "The error was:  {e}".format(e=e)
     )
 
-
 __author__ = 'Ero Carrera'
 __version__ = '2.0.0.dev0'
 __license__ = 'MIT'
 
-
 PY3 = sys.version_info >= (3, 0, 0)
 if PY3:
     str_type = str
 else:
     str_type = basestring
 
-
 GRAPH_ATTRIBUTES = {
-    'Damping',
-    'K',
-    'URL',
-    'aspect',
-    'bb',
-    'bgcolor',
-    'center',
-    'charset',
-    'clusterrank',
-    'colorscheme',
-    'comment',
-    'compound',
-    'concentrate',
-    'defaultdist',
-    'dim',
-    'dimen',
-    'diredgeconstraints',
-    'dpi',
-    'epsilon',
-    'esep',
-    'fontcolor',
-    'fontname',
-    'fontnames',
-    'fontpath',
-    'fontsize',
-    'id',
-    'label',
-    'labeljust',
-    'labelloc',
-    'landscape',
-    'layers',
-    'layersep',
-    'layout',
-    'levels',
-    'levelsgap',
-    'lheight',
-    'lp',
-    'lwidth',
-    'margin',
-    'maxiter',
-    'mclimit',
-    'mindist',
-    'mode',
-    'model',
-    'mosek',
-    'nodesep',
-    'nojustify',
-    'normalize',
-    'nslimit',
-    'nslimit1',
-    'ordering',
-    'orientation',
-    'outputorder',
-    'overlap',
-    'overlap_scaling',
-    'pack',
-    'packmode',
-    'pad',
-    'page',
-    'pagedir',
-    'quadtree',
-    'quantum',
-    'rankdir',
-    'ranksep',
-    'ratio',
-    'remincross',
-    'repulsiveforce',
-    'resolution',
-    'root',
-    'rotate',
-    'searchsize',
-    'sep',
-    'showboxes',
-    'size',
-    'smoothing',
-    'sortv',
-    'splines',
-    'start',
-    'stylesheet',
-    'target',
-    'truecolor',
-    'viewport',
-    'voro_margin',
-    # for subgraphs
-    'rank',
-}
-
+    'Damping', 'K', 'URL', 'aspect', 'bb', 'bgcolor', 'center', 'charset',
+    'clusterrank', 'colorscheme', 'comment', 'compound', 'concentrate',
+    'defaultdist', 'dim', 'dimen', 'diredgeconstraints', 'dpi', 'epsilon',
+    'esep', 'fontcolor', 'fontname', 'fontnames', 'fontpath', 'fontsize', 'id',
+    'label', 'labeljust', 'labelloc', 'landscape', 'layers', 'layersep',
+    'layout', 'levels', 'levelsgap', 'lheight', 'lp', 'lwidth', 'margin',
+    'maxiter', 'mclimit', 'mindist', 'mode', 'model', 'mosek', 'nodesep',
+    'nojustify', 'normalize', 'nslimit', 'nslimit1', 'ordering', 'orientation',
+    'outputorder', 'overlap', 'overlap_scaling', 'pack', 'packmode', 'pad',
+    'page', 'pagedir', 'quadtree', 'quantum', 'rankdir', 'ranksep', 'ratio',
+    'remincross', 'repulsiveforce', 'resolution', 'root', 'rotate',
+    'searchsize', 'sep', 'showboxes', 'size', 'smoothing', 'sortv', 'splines',
+    'start', 'stylesheet', 'target', 'truecolor', 'viewport', 'voro_margin'
+} | {'rank'}  # for subgraphs
 
 EDGE_ATTRIBUTES = {
-    'URL',
-    'arrowhead',
-    'arrowsize',
-    'arrowtail',
-    'color',
-    'colorscheme',
-    'comment',
-    'constraint',
-    'decorate',
-    'dir',
-    'edgeURL',
-    'edgehref',
-    'edgetarget',
-    'edgetooltip',
-    'fontcolor',
-    'fontname',
-    'fontsize',
-    'headURL',
-    'headclip',
-    'headhref',
-    'headlabel',
-    'headport',
-    'headtarget',
-    'headtooltip',
-    'href',
-    'id',
-    'label',
-    'labelURL',
-    'labelangle',
-    'labeldistance',
-    'labelfloat',
-    'labelfontcolor',
-    'labelfontname',
-    'labelfontsize',
-    'labelhref',
-    'labeltarget',
-    'labeltooltip',
-    'layer',
-    'len',
-    'lhead',
-    'lp',
-    'ltail',
-    'minlen',
-    'nojustify',
-    'penwidth',
-    'pos',
-    'samehead',
-    'sametail',
-    'showboxes',
-    'style',
-    'tailURL',
-    'tailclip',
-    'tailhref',
-    'taillabel',
-    'tailport',
-    'tailtarget',
-    'tailtooltip',
-    'target',
-    'tooltip',
-    'weight',
-    'rank',
+    'URL', 'arrowhead', 'arrowsize', 'arrowtail', 'color', 'colorscheme',
+    'comment', 'constraint', 'decorate', 'dir', 'edgeURL', 'edgehref',
+    'edgetarget', 'edgetooltip', 'fontcolor', 'fontname', 'fontsize',
+    'headURL', 'headclip', 'headhref', 'headlabel', 'headport', 'headtarget',
+    'headtooltip', 'href', 'id', 'label', 'labelURL', 'labelangle',
+    'labeldistance', 'labelfloat', 'labelfontcolor', 'labelfontname',
+    'labelfontsize', 'labelhref', 'labeltarget', 'labeltooltip', 'layer',
+    'len', 'lhead', 'lp', 'ltail', 'minlen', 'nojustify', 'penwidth', 'pos',
+    'samehead', 'sametail', 'showboxes', 'style', 'tailURL', 'tailclip',
+    'tailhref', 'taillabel', 'tailport', 'tailtarget', 'tailtooltip', 'target',
+    'tooltip', 'weight', 'rank'
 }
 
-
 NODE_ATTRIBUTES = {
-    'URL',
-    'color',
-    'colorscheme',
-    'comment',
-    'distortion',
-    'fillcolor',
-    'fixedsize',
-    'fontcolor',
-    'fontname',
-    'fontsize',
-    'group',
-    'height',
-    'id',
-    'image',
-    'imagescale',
-    'label',
-    'labelloc',
-    'layer',
-    'margin',
-    'nojustify',
-    'orientation',
-    'penwidth',
-    'peripheries',
-    'pin',
-    'pos',
-    'rects',
-    'regular',
-    'root',
-    'samplepoints',
-    'shape',
-    'shapefile',
-    'showboxes',
-    'sides',
-    'skew',
-    'sortv',
-    'style',
-    'target',
-    'tooltip',
-    'vertices',
-    'width',
-    'z',
-    # The following are attributes dot2tex
-    'texlbl',
-    'texmode',
-}
-
+    'URL', 'color', 'colorscheme', 'comment', 'distortion', 'fillcolor',
+    'fixedsize', 'fontcolor', 'fontname', 'fontsize', 'group', 'height', 'id',
+    'image', 'imagescale', 'label', 'labelloc', 'layer', 'margin', 'nojustify',
+    'orientation', 'penwidth', 'peripheries', 'pin', 'pos', 'rects', 'regular',
+    'root', 'samplepoints', 'shape', 'shapefile', 'showboxes', 'sides', 'skew',
+    'sortv', 'style', 'target', 'tooltip', 'vertices', 'width', 'z'
+} | {'texlbl', 'texmode'}  # The last set contains attributes dot2tex
 
 CLUSTER_ATTRIBUTES = {
-    'K',
-    'URL',
-    'bgcolor',
-    'color',
-    'colorscheme',
-    'fillcolor',
-    'fontcolor',
-    'fontname',
-    'fontsize',
-    'label',
-    'labeljust',
-    'labelloc',
-    'lheight',
-    'lp',
-    'lwidth',
-    'nojustify',
-    'pencolor',
-    'penwidth',
-    'peripheries',
-    'sortv',
-    'style',
-    'target',
-    'tooltip',
+    'K', 'URL', 'bgcolor', 'color', 'colorscheme', 'fillcolor', 'fontcolor',
+    'fontname', 'fontsize', 'label', 'labeljust', 'labelloc', 'lheight', 'lp',
+    'lwidth', 'nojustify', 'pencolor', 'penwidth', 'peripheries', 'sortv',
+    'style', 'target', 'tooltip'
 }
 
-
 DEFAULT_PROGRAMS = {
     'dot',
     'twopi',
@@ -280,7 +94,6 @@ def is_windows():
 def is_anaconda():
     # type: () -> bool
     import glob
-
     conda_pattern = os.path.join(sys.prefix, 'conda-meta\\graphviz*.json')
     return glob.glob(conda_pattern) != []
 
@@ -336,6 +149,7 @@ def call_graphviz(program, arguments, working_dir, **kwargs):
 # This version freezes dictionaries used as values within dictionaries.
 #
 class frozendict(dict):
+
     def _blocked_attribute(obj):
         raise AttributeError('A frozendict cannot be modified.')
 
@@ -417,16 +231,13 @@ def needs_quotes(s):
     if s in dot_keywords:
         return False
 
-    chars = [ord(c) for c in s if ord(c) > 0x7F or ord(c) == 0]
+    chars = [ord(c) for c in s if ord(c) > 0x7f or ord(c) == 0]
     if chars and not id_re_dbl_quoted.match(s) and not id_re_html.match(s):
         return True
 
     for test_re in [
-        id_re_alpha_nums,
-        id_re_num,
-        id_re_dbl_quoted,
-        id_re_html,
-        id_re_alpha_nums_with_ports,
+        id_re_alpha_nums, id_re_num, id_re_dbl_quoted, id_re_html,
+        id_re_alpha_nums_with_ports
     ]:
         if test_re.match(s):
             return False
@@ -560,7 +371,7 @@ def graph_from_adjacency_matrix(matrix, node_prefix=u'', directed=False):
                 graph.add_edge(
                     Edge(
                         '%s%s' % (node_prefix, node_orig),
-                        '%s%s' % (node_prefix, node_dest),
+                        '%s%s' % (node_prefix, node_dest)
                     )
                 )
             node_dest += 1
@@ -597,7 +408,7 @@ def graph_from_incidence_matrix(matrix, node_prefix='', directed=False):
             graph.add_edge(
                 Edge(
                     '%s%s' % (node_prefix, abs(nodes[0])),
-                    '%s%s' % (node_prefix, nodes[1]),
+                    '%s%s' % (node_prefix, nodes[1])
                 )
             )
 
@@ -708,9 +519,8 @@ def create_attribute_methods(self, obj_attributes):
             #
             self.__setattr__(
                 'set_' + attr,
-                lambda x, a=attr: self.obj_dict['attributes'].__setitem__(
-                    a, x
-                ),
+                lambda x, a=attr: self.obj_dict['attributes'].
+                __setitem__(a, x)
             )
 
             # Generate all the Getter methods.
@@ -721,7 +531,8 @@ def create_attribute_methods(self, obj_attributes):
 
 
 class Error(Exception):
-    """General error handling class."""
+    """General error handling class.
+    """
 
     def __init__(self, value):
         self.value = value
@@ -731,7 +542,8 @@ def __str__(self):
 
 
 class InvocationException(Exception):
-    """Indicate problem while running any GraphViz executable."""
+    """Indicate problem while running any GraphViz executable.
+    """
 
     def __init__(self, value):
         self.value = value
@@ -930,18 +742,20 @@ def __eq__(self, edge):
             # source nor destination.
             #
             if (
-                self.get_source() == edge.get_source()
-                and self.get_destination() == edge.get_destination()
-            ) or (
-                edge.get_source() == self.get_destination()
-                and edge.get_destination() == self.get_source()
+                (
+                    self.get_source() == edge.get_source() and
+                    self.get_destination() == edge.get_destination()
+                ) or (
+                    edge.get_source() == self.get_destination() and
+                    edge.get_destination() == self.get_source()
+                )
             ):
                 return True
 
         else:
             if (
-                self.get_source() == edge.get_source()
-                and self.get_destination() == edge.get_destination()
+                self.get_source() == edge.get_source() and
+                self.get_destination() == edge.get_destination()
             ):
                 return True
 
@@ -966,15 +780,14 @@ def parse_node_ref(self, node_str):
         node_port_idx = node_str.rfind(':')
 
         if (
-            node_port_idx > 0
-            and node_str[0] == '"'
-            and node_str[node_port_idx - 1] == '"'
+            node_port_idx > 0 and node_str[0] == '"' and
+            node_str[node_port_idx - 1] == '"'
         ):
             return node_str
 
         if node_port_idx > 0:
             a = node_str[:node_port_idx]
-            b = node_str[node_port_idx + 1 :]
+            b = node_str[node_port_idx + 1:]
 
             node = quote_if_necessary(a)
             node += ':' + quote_if_necessary(b)
@@ -996,9 +809,9 @@ def to_string(self):
             edge = [src]
 
         if (
-            self.get_parent_graph()
-            and self.get_parent_graph().get_top_graph_type()
-            and self.get_parent_graph().get_top_graph_type() == 'digraph'
+            self.get_parent_graph() and
+            self.get_parent_graph().get_top_graph_type() and
+            self.get_parent_graph().get_top_graph_type() == 'digraph'
         ):
             edge.append('->')
 
@@ -1242,9 +1055,8 @@ def add_node(self, graph_node):
         """
         if not isinstance(graph_node, Node):
             raise TypeError(
-                'add_node() received '
-                + 'a non node class object: '
-                + str(graph_node)
+                'add_node() received a non node class object: ' +
+                str(graph_node)
             )
 
         node = self.get_node(graph_node.get_name())
@@ -1283,7 +1095,10 @@ def del_node(self, name, index=None):
 
         if name in self.obj_dict['nodes']:
 
-            if index is not None and index < len(self.obj_dict['nodes'][name]):
+            if (
+                index is not None and
+                index < len(self.obj_dict['nodes'][name])
+            ):
                 del self.obj_dict['nodes'][name][index]
                 return True
             else:
@@ -1341,8 +1156,8 @@ def add_edge(self, graph_edge):
         """
         if not isinstance(graph_edge, Edge):
             raise TypeError(
-                'add_edge() received a non edge class object: '
-                + str(graph_edge)
+                'add_edge() received a non edge class object: ' +
+                str(graph_edge)
             )
 
         edge_points = (graph_edge.get_source(), graph_edge.get_destination())
@@ -1386,8 +1201,9 @@ def del_edge(self, src_or_list, dst=None, index=None):
             dst = dst.get_name()
 
         if (src, dst) in self.obj_dict['edges']:
-            if index is not None and index < len(
-                self.obj_dict['edges'][(src, dst)]
+            if (
+                index is not None and
+                index < len(self.obj_dict['edges'][(src, dst)])
             ):
                 del self.obj_dict['edges'][(src, dst)][index]
                 return True
@@ -1417,12 +1233,12 @@ def get_edge(self, src_or_list, dst=None):
         match = list()
 
         if edge_points in self.obj_dict['edges'] or (
-            self.get_top_graph_type() == 'graph'
-            and edge_points_reverse in self.obj_dict['edges']
+            self.get_top_graph_type() == 'graph' and
+            edge_points_reverse in self.obj_dict['edges']
         ):
             edges_obj_dict = self.obj_dict['edges'].get(
                 edge_points,
-                self.obj_dict['edges'].get(edge_points_reverse, None),
+                self.obj_dict['edges'].get(edge_points_reverse, None)
             )
 
             for edge_obj_dict in edges_obj_dict:
@@ -1457,12 +1273,13 @@ def add_subgraph(self, sgraph):
         It takes a subgraph object as its only argument and returns
         None.
         """
-        if not isinstance(sgraph, Subgraph) and not isinstance(
-            sgraph, Cluster
+        if (
+            not isinstance(sgraph, Subgraph) and
+            not isinstance(sgraph, Cluster)
         ):
             raise TypeError(
-                'add_subgraph() received a non subgraph class object:'
-                + str(sgraph)
+                'add_subgraph() received a non subgraph class object:' +
+                str(sgraph)
             )
 
         if sgraph.get_name() in self.obj_dict['subgraphs']:
@@ -1544,13 +1361,14 @@ def to_string(self):
 
         if self.obj_dict.get('strict', None) is not None:
 
-            if self == self.get_parent_graph() and self.obj_dict['strict']:
+            if (self == self.get_parent_graph() and self.obj_dict['strict']):
 
                 graph.append('strict ')
 
         graph_type = self.obj_dict['type']
-        if graph_type == 'subgraph' and not self.obj_dict.get(
-            'show_keyword', True
+        if (
+            graph_type == 'subgraph' and
+            not self.obj_dict.get('show_keyword', True)
         ):
             graph_type = ''
         s = '{type} {name} {{\n'.format(
@@ -1608,8 +1426,8 @@ def to_string(self):
                 if self.obj_dict.get('suppress_disconnected', False):
 
                     if (
-                        node.get_name() not in edge_src_set
-                        and node.get_name() not in edge_dst_set
+                        node.get_name() not in edge_src_set and
+                        node.get_name() not in edge_dst_set
                     ):
                         continue
 
@@ -1618,7 +1436,9 @@ def to_string(self):
             elif obj['type'] == 'edge':
                 edge = Edge(obj_dict=obj)
 
-                if self.obj_dict.get('simplify', False) and edge in edges_done:
+                if (
+                    self.obj_dict.get('simplify', False) and edge in edges_done
+                ):
                     continue
 
                 graph.append(edge.to_string() + '\n')
@@ -1760,42 +1580,11 @@ def __init__(self, *argsl, **argsd):
 
         self.shape_files = list()
         self.formats = [
-            'canon',
-            'cmap',
-            'cmapx',
-            'cmapx_np',
-            'dia',
-            'dot',
-            'fig',
-            'gd',
-            'gd2',
-            'gif',
-            'hpgl',
-            'imap',
-            'imap_np',
-            'ismap',
-            'jpe',
-            'jpeg',
-            'jpg',
-            'mif',
-            'mp',
-            'pcl',
-            'pdf',
-            'pic',
-            'plain',
-            'plain-ext',
-            'png',
-            'ps',
-            'ps2',
-            'svg',
-            'svgz',
-            'vml',
-            'vmlz',
-            'vrml',
-            'vtx',
-            'wbmp',
-            'xdot',
-            'xlib',
+            'canon', 'cmap', 'cmapx', 'cmapx_np', 'dia', 'dot', 'fig', 'gd',
+            'gd2', 'gif', 'hpgl', 'imap', 'imap_np', 'ismap', 'jpe', 'jpeg',
+            'jpg', 'mif', 'mp', 'pcl', 'pdf', 'pic', 'plain', 'plain-ext',
+            'png', 'ps', 'ps2', 'svg', 'svgz', 'vml', 'vmlz', 'vrml', 'vtx',
+            'wbmp', 'xdot', 'xlib'
         ]
 
         self.prog = 'dot'
@@ -1984,13 +1773,9 @@ def create(self, prog=None, format='ps', encoding=None):
             f.write(f_data)
             f.close()
 
-        arguments = (
-            [
-                '-T{}'.format(format),
-            ]
-            + args
-            + [tmp_name]
-        )
+        arguments = [
+            '-T{}'.format(format),
+        ] + args + [tmp_name]
 
         try:
             stdout_data, stderr_data, process = call_graphviz(
@@ -2025,12 +1810,12 @@ def create(self, prog=None, format='ps', encoding=None):
             )
             print(message)
 
-        assert (
-            process.returncode == 0
-        ), '"{prog}" with args {arguments} returned code: {code}'.format(
-            prog=prog,
-            arguments=arguments,
-            code=process.returncode,
+        assert process.returncode == 0, (
+            '"{prog}" with args {arguments} returned code: {code}'.format(
+                prog=prog,
+                arguments=arguments,
+                code=process.returncode,
+            )
         )
 
         return stdout_data
diff --git a/setup.py b/setup.py
index ae3d3eeb..054deb3e 100644
--- a/setup.py
+++ b/setup.py
@@ -10,7 +10,6 @@
 import os
 import re
 
-
 CURRENT_DIR = os.path.dirname(__file__)
 
 
@@ -69,5 +68,5 @@ def get_version():
     long_description_content_type="text/markdown",
     py_modules=['pydot', 'dot_parser'],
     install_requires=['pyparsing>=2.1.4'],
-    tests_require=['chardet'],
+    tests_require=['chardet']
 )
diff --git a/test/pydot_unittest.py b/test/pydot_unittest.py
index df3b3f1b..cd33e132 100644
--- a/test/pydot_unittest.py
+++ b/test/pydot_unittest.py
@@ -19,13 +19,13 @@
 import pydot
 import unittest
 
-
 TEST_PROGRAM = 'dot'
 TESTS_DIR_1 = 'my_tests'
 TESTS_DIR_2 = 'graphs'
 
 
 class TestGraphAPI(unittest.TestCase):
+
     def setUp(self):
         self._reset_graphs()
 
@@ -62,7 +62,7 @@ def test_create_simple_graph_with_node(self):
     def test_attribute_with_implicit_value(self):
         d = 'digraph {\na -> b[label="hi", decorate];\n}'
         graphs = pydot.graph_from_dot_data(d)
-        (g,) = graphs
+        (g, ) = graphs
         attrs = g.get_edges()[0].get_attributes()
 
         self.assertEqual('decorate' in attrs, True)
@@ -105,7 +105,7 @@ def test_unicode_ids(self):
         self.assertEqual(g.get_edges()[0].get_source(), node1)
         self.assertEqual(g.get_edges()[0].get_destination(), node2)
         graphs = pydot.graph_from_dot_data(g.to_string())
-        (g2,) = graphs
+        (g2, ) = graphs
 
         self.assertEqual(g2.get_node(node1)[0].get_name(), node1)
         self.assertEqual(g2.get_node(node2)[0].get_name(), node2)
@@ -125,8 +125,7 @@ def test_graph_simplify(self):
                 'graph',
                 False,
                 'graph G { a -- b; a -- b; b -- a; b -- a; }',
-            ),
-            (
+            ), (
                 'graph',
                 True,
                 'graph G { a -- b; }',
@@ -135,19 +134,16 @@ def test_graph_simplify(self):
                 'digraph',
                 False,
                 'digraph G { a -> b; a -> b; b -> a; b -> a; }',
-            ),
-            (
+            ), (
                 'digraph',
                 True,
                 'digraph G { a -> b; b -> a; }',
-            ),
+            )
         ]
         expected_concat = observed_concat = ''
         for (graph_type, simplify, expected) in test_combinations:
             expected_concat += 'graph_type %s, simplify %s: %s\n' % (
-                graph_type,
-                simplify,
-                expected,
+                graph_type, simplify, expected
             )
             g.set_type(graph_type)
             g.set_simplify(simplify)
@@ -156,9 +152,7 @@ def test_graph_simplify(self):
             except (NameError, TypeError) as e:
                 observed = '%s: %s' % (type(e).__name__, e)
             observed_concat += 'graph_type %s, simplify %s: %s\n' % (
-                graph_type,
-                simplify,
-                observed,
+                graph_type, simplify, observed
             )
         self.maxDiff = None
         self.assertMultiLineEqual(expected_concat, observed_concat)
@@ -176,8 +170,7 @@ def test_graph_with_shapefiles(self):
 
         pngs = [
             os.path.join(shapefile_dir, fname)
-            for fname in os.listdir(shapefile_dir)
-            if fname.endswith('.png')
+            for fname in os.listdir(shapefile_dir) if fname.endswith('.png')
         ]
 
         f = open(dot_file, 'rt')
@@ -185,7 +178,7 @@ def test_graph_with_shapefiles(self):
         f.close()
 
         graphs = pydot.graph_from_dot_data(graph_data)
-        (g,) = graphs
+        (g, ) = graphs
         g.set_shape_files(pngs)
 
         jpe_data = g.create(format='jpe')
@@ -291,12 +284,13 @@ def test_keyword_node_id_to_string_with_attributes(self):
 
     def test_names_of_a_thousand_nodes(self):
         self._reset_graphs()
-        names = {'node_%05d' % i for i in range(10 ** 3)}
+        names = {'node_%05d' % i for i in range(10**3)}
         for name in names:
             self.graph_directed.add_node(pydot.Node(name, label=name))
 
         self.assertEqual(
-            {n.get_name() for n in self.graph_directed.get_nodes()}, names
+            {n.get_name()
+             for n in self.graph_directed.get_nodes()}, names
         )
 
     def test_executable_not_found_exception(self):
@@ -371,7 +365,7 @@ def test_edge_point_object_cluster(self):
         )
         self.assertEqual(
             self.graph_directed.get_edges()[0].to_string(),
-            'cluster_a -> cluster_b;',
+            'cluster_a -> cluster_b;'
         )
 
     def test_graph_from_adjacency_matrix(self):
@@ -403,9 +397,10 @@ def check_path():
     not_check = parse_args()
     if not_check:
         return
-    assert not os.path.isfile(
-        'setup.py'
-    ), 'running out of source does not test the installed `pydot`.'
+    assert not os.path.isfile('setup.py'), (
+        'running out of source does not '
+        'test the installed `pydot`.'
+    )
 
 
 def parse_args():
@@ -417,7 +412,7 @@ def parse_args():
         help=(
             'do not require that no `setup.py` be present '
             'in the current working directory.'
-        ),
+        )
     )
     args, unknown = parser.parse_known_args()
     # avoid confusing `unittest`