Drop support for Python 2.6 (#356)

Fixes #330

Author: willkg

Diff for: .travis.yml

@@ -1,6 +1,5 @@
 language: python
 python:
-  - "2.6"
   - "2.7"
   - "3.3"
   - "3.4"

Diff for: README.rst

@@ -90,7 +90,7 @@ More documentation is available at https://html5lib.readthedocs.io/.
 Installation
 ------------
 
-html5lib works on CPython 2.6+, CPython 3.3+ and PyPy.  To install it,
+html5lib works on CPython 2.7+, CPython 3.3+ and PyPy.  To install it,
 use:
 
 .. code-block:: bash
@@ -128,8 +128,7 @@ Tests
 -----
 
 Unit tests require the ``pytest`` and ``mock`` libraries and can be
-run using the ``py.test`` command in the root directory;
-``ordereddict`` is required under Python 2.6. All should pass.
+run using the ``py.test`` command in the root directory.
 
 Test data are contained in a separate `html5lib-tests
 <https://github.com/html5lib/html5lib-tests>`_ repository and included

Diff for: html5lib/_trie/_base.py

@@ -13,8 +13,7 @@ def keys(self, prefix=None):
         if prefix is None:
             return set(keys)
 
-        # Python 2.6: no set comprehensions
-        return set([x for x in keys if x.startswith(prefix)])
+        return {x for x in keys if x.startswith(prefix)}
 
     def has_keys_with_prefix(self, prefix):
         for key in self.keys():

Diff for: html5lib/filters/alphabeticalattributes.py

@@ -2,10 +2,7 @@
 
 from . import base
 
-try:
-    from collections import OrderedDict
-except ImportError:
-    from ordereddict import OrderedDict
+from collections import OrderedDict
 
 
 def _attr_key(attr):

Diff for: html5lib/html5parser.py

@@ -2,11 +2,7 @@
 from six import with_metaclass, viewkeys, PY3
 
 import types
-
-try:
-    from collections import OrderedDict
-except ImportError:
-    from ordereddict import OrderedDict
+from collections import OrderedDict
 
 from . import _inputstream
 from . import _tokenizer

Diff for: html5lib/tests/test_alphabeticalattributes.py

@@ -1,9 +1,6 @@
 from __future__ import absolute_import, division, unicode_literals
 
-try:
-    from collections import OrderedDict
-except ImportError:
-    from ordereddict import OrderedDict
+from collections import OrderedDict
 
 import pytest
 

Diff for: html5lib/treewalkers/etree.py

@@ -1,13 +1,6 @@
 from __future__ import absolute_import, division, unicode_literals
 
-try:
-    from collections import OrderedDict
-except ImportError:
-    try:
-        from ordereddict import OrderedDict
-    except ImportError:
-        OrderedDict = dict
-
+from collections import OrderedDict
 import re
 
 from six import string_types

Diff for: requirements.txt

@@ -1,3 +1,2 @@
 six>=1.9
 webencodings
-ordereddict ; python_version < '2.7'

Diff for: setup.py

@@ -64,7 +64,6 @@ def default_environment():
     'Operating System :: OS Independent',
     'Programming Language :: Python',
     'Programming Language :: Python :: 2',
-    'Programming Language :: Python :: 2.6',
     'Programming Language :: Python :: 2.7',
     'Programming Language :: Python :: 3',
     'Programming Language :: Python :: 3.3',
@@ -107,10 +106,6 @@ def default_environment():
           'webencodings',
       ],
       extras_require={
-          # A empty extra that only has a conditional marker will be
-          # unconditonally installed when the condition matches.
-          ":python_version == '2.6'": ["ordereddict"],
-
           # A conditional extra will only install these items when the extra is
           # requested and the condition matches.
           "datrie:platform_python_implementation == 'CPython'": ["datrie"],

Diff for: tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = {py26,py27,py33,py34,py35,py36,pypy}-{base,optional}
+envlist = {py27,py33,py34,py35,py36,pypy}-{base,optional}
 
 [testenv]
 deps =
@@ -9,7 +9,6 @@ deps =
   mock
   base: six
   base: webencodings
-  py26-base: ordereddict
   optional: -r{toxinidir}/requirements-optional.txt
   doc: Sphinx