Fix more flake8 issues.

It turns out flake8's behaviour differs between Python 2 and Python 3
because of the changes between the two, so run it on both on Travis.

.travis.yml

@@ -12,9 +12,13 @@ env:
 
 matrix:
   exclude:
+    - python: "2.7"
+      env: USE_OPTIONAL=false
     - python: "3.3"
       env: USE_OPTIONAL=false
   include:
+    - python: "2.7"
+      env: USE_OPTIONAL=false FLAKE=true
     - python: "3.3"
       env: USE_OPTIONAL=false FLAKE=true
 

html5lib/tests/tokenizertotree.py

@@ -25,7 +25,7 @@ def main(out_path):
 
 def run_file(filename, out_path):
     try:
-        tests_data = json.load(file(filename))
+        tests_data = json.load(open(filename, "r"))
     except ValueError:
         sys.stderr.write("Failed to load %s\n" % filename)
         return

html5lib/tokenizer.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import, division, unicode_literals
 
 try:
-    chr = unichr
+    chr = unichr # flake8: noqa
 except NameError:
     pass
 

html5lib/treebuilders/etree.py

@@ -255,7 +255,7 @@ def tostring(element):
         filter = ihatexml.InfosetFilter()
 
         def serializeElement(element):
-            if type(element) == type(ElementTree.ElementTree):
+            if isinstance(element, ElementTree.ElementTree):
                 element = element.getroot()
 
             if element.tag == "<!DOCTYPE>":

html5lib/treebuilders/etree_lxml.py

@@ -86,7 +86,7 @@ def serializeElement(element, indent=0):
                 rv.append("#document-fragment")
                 for next_element in element:
                     serializeElement(next_element, indent + 2)
-        elif type(element.tag) == type(etree.Comment):
+        elif isinstance(element.tag, etree.Comment):
             rv.append("|%s<!-- %s -->" % (' ' * indent, element.text))
             if hasattr(element, "tail") and element.tail:
                 rv.append("|%s\"%s\"" % (' ' * indent, element.tail))
@@ -149,7 +149,7 @@ def serializeElement(element):
                 rv.append(dtd_str)
             serializeElement(element.getroot())
 
-        elif type(element.tag) == type(etree.Comment):
+        elif isinstance(element.tag, etree.Comment):
             rv.append("<!--%s-->" % (element.text,))
 
         else:
@@ -301,7 +301,7 @@ def insertCommentInitial(self, data, parent=None):
 
     def insertCommentMain(self, data, parent=None):
         if (parent == self.document and
-                type(self.document._elementTree.getroot()[-1].tag) == type(etree.Comment)):
+                isinstance(self.document._elementTree.getroot()[-1].tag, etree.Comment)):
                 warnings.warn("lxml cannot represent adjacent comments beyond the root elements", DataLossWarning)
         super(TreeBuilder, self).insertComment(data, parent)