Merge with defaultpython_6

28 files changed, 166 insertions, 135 deletions

diff --git a/ChangeLog b/ChangeLog
index d9276d8..5ae6341 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,9 @@ ChangeLog for Pylint
 ====================
 
 --
+    * Port source code to be Python 2/3 compatible. This drops the
+      need for 2to3, but does drop support for Python 2.5.
+
     * Each message now comes with a confidence level attached, and
       can be filtered base on this level. This allows to filter out
       all messages that were emitted even though an inference failure
diff --git a/__pkginfo__.py b/__pkginfo__.py
index 757bfe9..255c6c1 100644
--- a/__pkginfo__.py
+++ b/__pkginfo__.py
@@ -22,11 +22,9 @@ modname = distname = 'pylint'
 numversion = (1, 3, 0)
 version = '.'.join([str(num) for num in numversion])
 
+install_requires = ['logilab-common >= 0.53.0', 'astroid >= 1.2', 'six']
 if sys.version_info < (2, 6):
-    install_requires = ['logilab-common >= 0.53.0', 'astroid >= 1.2',
-                        'StringFormat']
-else:
-    install_requires = ['logilab-common >= 0.53.0', 'astroid >= 1.2']
+    install_requires.append('StringFormat')
 
 license = 'GPL'
 description = "python code static checker"
diff --git a/checkers/base.py b/checkers/base.py
index 298ac5f..501d930 100644
--- a/checkers/base.py
+++ b/checkers/base.py
@@ -43,6 +43,8 @@ from pylint.checkers.utils import (
 
 
 import re
+import six
+from six.moves import zip
 
 # regex for class/function/variable/constant name
 CLASS_NAME_RGX = re.compile('[A-Z_][a-zA-Z0-9]+$')
@@ -175,7 +177,7 @@ def decorated_with_abc(func):
     if func.decorators:
         for node in func.decorators.nodes:
             try:
-                infered = node.infer().next()
+                infered = next(node.infer())
             except InferenceError:
                 continue
             if infered and infered.qname() in ABC_METHODS:
@@ -380,7 +382,7 @@ class BasicErrorChecker(_BasicChecker):
         abc.ABCMeta as metaclass.
         """
         try:
-            infered = node.func.infer().next()
+            infered = next(node.func.infer())
         except astroid.InferenceError:
             return
         if not isinstance(infered, astroid.Class):
@@ -576,7 +578,7 @@ functions, methods
         """check for various kind of statements without effect"""
         expr = node.value
         if isinstance(expr, astroid.Const) and isinstance(expr.value,
-                                                          basestring):
+                                                          six.string_types):
             # treat string statement in a separated message
             # Handle PEP-257 attribute docstrings.
             # An attribute docstring is defined as being a string right after
@@ -653,7 +655,7 @@ functions, methods
         # ordinary_args[i].name == call.args[i].name.
         if len(ordinary_args) != len(call.args):
             return
-        for i in xrange(len(ordinary_args)):
+        for i in range(len(ordinary_args)):
             if not isinstance(call.args[i], astroid.Name):
                 return
             if node.args.args[i].name != call.args[i].name:
@@ -674,7 +676,7 @@ functions, methods
         # check for dangerous default values as arguments
         for default in node.args.defaults:
             try:
-                value = default.infer().next()
+                value = next(default.infer())
             except astroid.InferenceError:
                 continue
 
@@ -840,7 +842,7 @@ functions, methods
                 # Try to see if we have iter().
                 if isinstance(node.args[0], astroid.CallFunc):
                     try:
-                        func = node.args[0].func.infer().next()
+                        func = next(node.args[0].func.infer())
                     except InferenceError:
                         return
                     if (getattr(func, 'name', None) == 'iter' and
@@ -893,7 +895,7 @@ _NAME_TYPES = {
 
 def _create_naming_options():
     name_options = []
-    for name_type, (rgx, human_readable_name) in _NAME_TYPES.iteritems():
+    for name_type, (rgx, human_readable_name) in six.iteritems(_NAME_TYPES):
         name_type = name_type.replace('_', '-')
         name_options.append((
             '%s-rgx' % (name_type,),
@@ -968,12 +970,12 @@ class NameChecker(_BasicChecker):
         self._bad_names = {}
 
     def leave_module(self, node):
-        for category, all_groups in self._bad_names.iteritems():
+        for category, all_groups in six.iteritems(self._bad_names):
             if len(all_groups) < 2:
                 continue
             groups = collections.defaultdict(list)
-            min_warnings = sys.maxint
-            for group in all_groups.itervalues():
+            min_warnings = sys.maxsize
+            for group in six.itervalues(all_groups):
                 groups[len(group)].append(group)
                 min_warnings = min(len(group), min_warnings)
             if len(groups[min_warnings]) > 1:
@@ -988,7 +990,7 @@ class NameChecker(_BasicChecker):
     @check_messages('blacklisted-name', 'invalid-name')
     def visit_class(self, node):
         self._check_name('class', node.name, node)
-        for attr, anodes in node.instance_attrs.iteritems():
+        for attr, anodes in six.iteritems(node.instance_attrs):
             if not list(node.instance_attr_ancestors(attr)):
                 self._check_name('attr', attr, anodes[0])
 
diff --git a/checkers/classes.py b/checkers/classes.py
index aa05558..d9b7581 100644
--- a/checkers/classes.py
+++ b/checkers/classes.py
@@ -28,6 +28,7 @@ from pylint.checkers import BaseChecker
 from pylint.checkers.utils import (
     PYMETHODS, overrides_a_method, check_messages, is_attr_private,
     is_attr_protected, node_frame_class, safe_infer, is_builtin_object)
+import six
 
 if sys.version_info >= (3, 0):
     NEXT_METHOD = '__next__'
@@ -298,7 +299,7 @@ a metaclass class method.'}
             return
         defining_methods = self.config.defining_attr_methods
         current_module = cnode.root()
-        for attr, nodes in cnode.instance_attrs.iteritems():
+        for attr, nodes in six.iteritems(cnode.instance_attrs):
             # skip nodes which are not in the current module and it may screw up
             # the output, while it's not worth it
             nodes = [n for n in nodes if not
@@ -612,7 +613,7 @@ a metaclass class method.'}
     def _check_accessed_members(self, node, accessed):
         """check that accessed members are defined"""
         # XXX refactor, probably much simpler now that E0201 is in type checker
-        for attr, nodes in accessed.iteritems():
+        for attr, nodes in six.iteritems(accessed):
             # deactivate "except doesn't do anything", that's expected
             # pylint: disable=W0704
             try:
@@ -624,7 +625,7 @@ a metaclass class method.'}
                 pass
             # is it an instance attribute of a parent class ?
             try:
-                node.instance_attr_ancestors(attr).next()
+                next(node.instance_attr_ancestors(attr))
                 # yes, stop here
                 continue
             except StopIteration:
@@ -816,7 +817,7 @@ a metaclass class method.'}
                expr.expr.func.name == 'super':
                 return
             try:
-                klass = expr.expr.infer().next()
+                klass = next(expr.expr.infer())
                 if klass is YES:
                     continue
                 # The infered klass can be super(), which was
@@ -838,7 +839,7 @@ a metaclass class method.'}
                                          node=expr, args=klass.name)
             except astroid.InferenceError:
                 continue
-        for klass, method in not_called_yet.iteritems():
+        for klass, method in six.iteritems(not_called_yet):
             if klass.name == 'object' or method.parent.name == 'object':
                 continue
             self.add_message('super-init-not-called', args=klass.name, node=node)
@@ -880,7 +881,7 @@ def _ancestors_to_call(klass_node, method='__init__'):
     to_call = {}
     for base_node in klass_node.ancestors(recurs=False):
         try:
-            to_call[base_node] = base_node.igetattr(method).next()
+            to_call[base_node] = next(base_node.igetattr(method))
         except astroid.InferenceError:
             continue
     return to_call
diff --git a/checkers/exceptions.py b/checkers/exceptions.py
index 9b1a071..f9b78bb 100644
--- a/checkers/exceptions.py
+++ b/checkers/exceptions.py
@@ -67,7 +67,7 @@ def infer_bases(klass):
     """
     for base in klass.bases:
         try:
-            inferit = base.infer().next()
+            inferit = next(base.infer())
         except astroid.InferenceError:
             continue
         if inferit is YES:
@@ -178,7 +178,7 @@ class ExceptionsChecker(BaseChecker):
             return
         if PY3K and node.cause:
             try:
-                cause = node.cause.infer().next()
+                cause = next(node.cause.infer())
             except astroid.InferenceError:
                 pass
             else:
@@ -197,7 +197,7 @@ class ExceptionsChecker(BaseChecker):
             return
         else:
             try:
-                value = unpack_infer(expr).next()
+                value = next(unpack_infer(expr))
             except astroid.InferenceError:
                 return
             self._check_raise_value(node, value)
diff --git a/checkers/format.py b/checkers/format.py
index 34da653..134999e 100644
--- a/checkers/format.py
+++ b/checkers/format.py
@@ -24,6 +24,9 @@ Some parts of the process_token method is based from The Tab Nanny std module.
 import keyword
 import sys
 import tokenize
+from functools import reduce
+import six
+from six.moves import zip
 
 if not hasattr(tokenize, 'NL'):
     raise ValueError("tokenize.NL doesn't exist -- tokenize module too old")
@@ -342,7 +345,8 @@ class ContinuedLineState(object):
             # current indent level
             paren_align = self._cont_stack[-1].valid_outdent_offsets
             next_align = self._cont_stack[-1].valid_continuation_offsets.copy()
-            next_align[next_align.keys()[0] + self._continuation_size] = True
+            next_align_keys = list(next_align.keys())
+            next_align[next_align_keys[0] + self._continuation_size] = True
             # Note that the continuation of
             # d = {
             #       'a': 'b'
@@ -506,7 +510,7 @@ class FormatChecker(BaseTokenChecker):
         keyword_token = tokens[start][1]
         line_num = tokens[start][2][0]
 
-        for i in xrange(start, len(tokens) - 1):
+        for i in range(start, len(tokens) - 1):
             token = tokens[i]
 
             # If we hit a newline, then assume any parens were for continuation.
@@ -812,7 +816,7 @@ class FormatChecker(BaseTokenChecker):
 
         for indent_pos, state, offsets in self._current_line.retained_warnings:
             block_type = offsets[tokens.start_col(indent_pos)]
-            hints = dict((k, v) for k, v in offsets.iteritems()
+            hints = dict((k, v) for k, v in six.iteritems(offsets)
                          if v != block_type)
             if single_line_block_stmt and block_type == WITH_BODY:
                 self._add_continuation_message(state, hints, tokens, indent_pos)
@@ -886,7 +890,7 @@ class FormatChecker(BaseTokenChecker):
             tolineno = node.tolineno
         assert tolineno, node
         lines = []
-        for line in xrange(line, tolineno + 1):
+        for line in range(line, tolineno + 1):
             self._visited_lines[line] = 1
             try:
                 lines.append(self._lines[line].rstrip())
diff --git a/checkers/imports.py b/checkers/imports.py
index a861ce6..4369b02 100644
--- a/checkers/imports.py
+++ b/checkers/imports.py
@@ -28,6 +28,8 @@ from pylint.interfaces import IAstroidChecker
 from pylint.utils import EmptyReport
 from pylint.checkers import BaseChecker
 from pylint.checkers.utils import check_messages, is_import_error
+import six
+from six.moves import map
 
 def _except_import_error(node):
     """
@@ -106,14 +108,14 @@ def dependencies_graph(filename, dep_info):
     done = {}
     printer = DotBackend(filename[:-4], rankdir='LR')
     printer.emit('URL="." node[shape="box"]')
-    for modname, dependencies in sorted(dep_info.iteritems()):
+    for modname, dependencies in sorted(six.iteritems(dep_info)):
         done[modname] = 1
         printer.emit_node(modname)
         for modname in dependencies:
             if modname not in done:
                 done[modname] = 1
                 printer.emit_node(modname)
-    for depmodname, dependencies in sorted(dep_info.iteritems()):
+    for depmodname, dependencies in sorted(six.iteritems(dep_info)):
         for modname in dependencies:
             printer.emit_edge(modname, depmodname)
     printer.generate(filename)
@@ -281,7 +283,7 @@ given file (report RP0402 must not be disabled)'}
     def get_imported_module(self, modnode, importnode, modname):
         try:
             return importnode.do_import_module(modname)
-        except astroid.InferenceError, ex:
+        except astroid.InferenceError as ex:
             if str(ex) != modname:
                 args = '%r (%s)' % (modname, ex)
             else:
@@ -353,7 +355,7 @@ given file (report RP0402 must not be disabled)'}
 
     def report_external_dependencies(self, sect, _, dummy):
         """return a verbatim layout for displaying dependencies"""
-        dep_info = make_tree_defs(self._external_dependencies_info().iteritems())
+        dep_info = make_tree_defs(six.iteritems(self._external_dependencies_info()))
         if not dep_info:
             raise EmptyReport()
         tree_str = repr_tree_defs(dep_info)
@@ -385,7 +387,7 @@ given file (report RP0402 must not be disabled)'}
         if self.__ext_dep_info is None:
             package = self.linter.current_name
             self.__ext_dep_info = result = {}
-            for importee, importers in self.stats['dependencies'].iteritems():
+            for importee, importers in six.iteritems(self.stats['dependencies']):
                 if not importee.startswith(package):
                     result[importee] = importers
         return self.__ext_dep_info
@@ -397,7 +399,7 @@ given file (report RP0402 must not be disabled)'}
         if self.__int_dep_info is None:
             package = self.linter.current_name
             self.__int_dep_info = result = {}
-            for importee, importers in self.stats['dependencies'].iteritems():
+            for importee, importers in six.iteritems(self.stats['dependencies']):
                 if importee.startswith(package):
                     result[importee] = importers
         return self.__int_dep_info
diff --git a/checkers/logging.py b/checkers/logging.py
index d82d74b..39c4d9c 100644
--- a/checkers/logging.py
+++ b/checkers/logging.py
@@ -20,6 +20,9 @@ from pylint import interfaces
 from pylint.checkers import utils
 from pylint.checkers.utils import check_messages
 
+import six
+
+
 MSGS = {
     'W1201': ('Specify string format arguments as logging function parameters',
               'logging-not-lazy',
@@ -166,7 +169,7 @@ class LoggingChecker(checkers.BaseChecker):
             # don't check any further.
             return
         format_string = node.args[format_arg].value
-        if not isinstance(format_string, basestring):
+        if not isinstance(format_string, six.string_types):
             # If the log format is constant non-string (e.g. logging.debug(5)),
             # ensure there are no arguments.
             required_num_args = 0
@@ -178,7 +181,7 @@ class LoggingChecker(checkers.BaseChecker):
                     # Keyword checking on logging strings is complicated by
                     # special keywords - out of scope.
                     return
-            except utils.UnsupportedFormatCharacter, ex:
+            except utils.UnsupportedFormatCharacter as ex:
                 char = format_string[ex.index]
                 self.add_message('logging-unsupported-format', node=node,
                                  args=(char, ord(char), ex.index))
diff --git a/checkers/misc.py b/checkers/misc.py
index b27b86a..d4adfd7 100644
--- a/checkers/misc.py
+++ b/checkers/misc.py
@@ -21,6 +21,7 @@ import re
 
 from pylint.interfaces import IRawChecker
 from pylint.checkers import BaseChecker
+import six
 
 
 MSGS = {
@@ -72,8 +73,8 @@ class EncodingChecker(BaseChecker):
 
     def _check_encoding(self, lineno, line, file_encoding):
         try:
-            return unicode(line, file_encoding)
-        except UnicodeDecodeError, ex:
+            return six.text_type(line, file_encoding)
+        except UnicodeDecodeError as ex:
             self.add_message('invalid-encoded-data', line=lineno,
                              args=(file_encoding, ex.args[2]))
 
diff --git a/checkers/newstyle.py b/checkers/newstyle.py
index 1946f94..335b052 100644
--- a/checkers/newstyle.py
+++ b/checkers/newstyle.py
@@ -133,7 +133,7 @@ class NewStyleConflictChecker(BaseChecker):
                         continue
 
                     try:
-                        supcls = (call.args and call.args[0].infer().next()
+                        supcls = (call.args and next(call.args[0].infer())
                                   or None)
                     except astroid.InferenceError:
                         continue
diff --git a/checkers/similar.py b/checkers/similar.py
index e5c9300..2cc2e00 100644
--- a/checkers/similar.py
+++ b/checkers/similar.py
@@ -16,14 +16,17 @@
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 """a similarities / code duplication command line tool and pylint checker
 """
+from __future__ import print_function
 import sys
-from itertools import izip
 
 from logilab.common.ureports import Table
 
 from pylint.interfaces import IRawChecker
 from pylint.checkers import BaseChecker, table_lines_from_stats
 
+import six
+from six.moves import zip
+
 
 class Similar(object):
     """finds copy-pasted lines of code in a project"""
@@ -69,7 +72,7 @@ class Similar(object):
             else:
                 duplicate.append(set([(lineset1, idx1), (lineset2, idx2)]))
         sims = []
-        for num, ensembles in no_duplicates.iteritems():
+        for num, ensembles in six.iteritems(no_duplicates):
             for couples in ensembles:
                 sims.append((num, couples))
         sims.sort()
@@ -80,19 +83,19 @@ class Similar(object):
         """display computed similarities on stdout"""
         nb_lignes_dupliquees = 0
         for num, couples in sims:
-            print
-            print num, "similar lines in", len(couples), "files"
+            print()
+            print(num, "similar lines in", len(couples), "files")
             couples = sorted(couples)
             for lineset, idx in couples:
-                print "==%s:%s" % (lineset.name, idx)
+                print("==%s:%s" % (lineset.name, idx))
             # pylint: disable=W0631
             for line in lineset._real_lines[idx:idx+num]:
-                print "  ", line.rstrip()
+                print("  ", line.rstrip())
             nb_lignes_dupliquees += num * (len(couples)-1)
         nb_total_lignes = sum([len(lineset) for lineset in self.linesets])
-        print "TOTAL lines=%s duplicates=%s percent=%.2f" \
+        print("TOTAL lines=%s duplicates=%s percent=%.2f" \
             % (nb_total_lignes, nb_lignes_dupliquees,
-               nb_lignes_dupliquees*100. / nb_total_lignes)
+               nb_lignes_dupliquees*100. / nb_total_lignes))
 
     def _find_common(self, lineset1, lineset2):
         """find similarities in the two given linesets"""
@@ -107,7 +110,7 @@ class Similar(object):
             for index2 in find(lineset1[index1]):
                 non_blank = 0
                 for num, ((_, line1), (_, line2)) in enumerate(
-                        izip(lines1(index1), lines2(index2))):
+                        zip(lines1(index1), lines2(index2))):
                     if line1 != line2:
                         if non_blank > min_lines:
                             yield num, lineset1, index1, lineset2, index2
@@ -323,10 +326,10 @@ def register(linter):
 
 def usage(status=0):
     """display command line usage information"""
-    print "finds copy pasted blocks in a set of files"
-    print
-    print 'Usage: symilar [-d|--duplicates min_duplicated_lines] \
-[-i|--ignore-comments] [--ignore-docstrings] [--ignore-imports] file1...'
+    print("finds copy pasted blocks in a set of files")
+    print()
+    print('Usage: symilar [-d|--duplicates min_duplicated_lines] \
+[-i|--ignore-comments] [--ignore-docstrings] [--ignore-imports] file1...')
     sys.exit(status)
 
 def Run(argv=None):
diff --git a/checkers/strings.py b/checkers/strings.py
index 40995f6..03c557a 100644
--- a/checkers/strings.py
+++ b/checkers/strings.py
@@ -30,6 +30,9 @@ from pylint.checkers import BaseChecker, BaseTokenChecker
 from pylint.checkers import utils
 from pylint.checkers.utils import check_messages
 
+import six
+
+
 _PY3K = sys.version_info[:2] >= (3, 0)
 _PY27 = sys.version_info[:2] == (2, 7)
 
@@ -231,13 +234,13 @@ class StringFormatChecker(BaseChecker):
         args = node.right
 
         if not (isinstance(left, astroid.Const)
-                and isinstance(left.value, basestring)):
+                and isinstance(left.value, six.string_types)):
             return
         format_string = left.value
         try:
             required_keys, required_num_args = \
                 utils.parse_format_string(format_string)
-        except utils.UnsupportedFormatCharacter, e:
+        except utils.UnsupportedFormatCharacter as e:
             c = format_string[e.index]
             self.add_message('bad-format-character',
                              node=node, args=(c, ord(c), e.index))
@@ -260,7 +263,7 @@ class StringFormatChecker(BaseChecker):
                 for k, _ in args.items:
                     if isinstance(k, astroid.Const):
                         key = k.value
-                        if isinstance(key, basestring):
+                        if isinstance(key, six.string_types):
                             keys.add(key)
                         else:
                             self.add_message('bad-format-string-key',
@@ -346,7 +349,7 @@ class StringMethodsChecker(BaseChecker):
         if not isinstance(node.func.expr, astroid.Const):
             return
         try:
-            strnode = func.bound.infer().next()
+            strnode = next(func.bound.infer())
         except astroid.InferenceError:
             return
         if not isinstance(strnode, astroid.Const):
@@ -365,7 +368,7 @@ class StringMethodsChecker(BaseChecker):
             return
 
         named_fields = set(field[0] for field in fields
-                           if isinstance(field[0], basestring))
+                           if isinstance(field[0], six.string_types))
         if num_args and manual_pos:
             self.add_message('format-combined-specification',
                              node=node)
@@ -435,7 +438,7 @@ class StringMethodsChecker(BaseChecker):
             if argname in (astroid.YES, None):
                 continue
             try:
-                argument = argname.infer().next()
+                argument = next(argname.infer())
             except astroid.InferenceError:
                 continue
             if not specifiers or argument is astroid.YES:
@@ -492,7 +495,7 @@ class StringMethodsChecker(BaseChecker):
                         break
 
                 try:
-                    previous = previous.infer().next()
+                    previous = next(previous.infer())
                 except astroid.InferenceError:
                     # can't check further if we can't infer it
                     break
diff --git a/checkers/utils.py b/checkers/utils.py
index af1440d..55bcdd4 100644
--- a/checkers/utils.py
+++ b/checkers/utils.py
@@ -87,11 +87,11 @@ def safe_infer(node):
     """
     try:
         inferit = node.infer()
-        value = inferit.next()
+        value = next(inferit)
     except astroid.InferenceError:
         return
     try:
-        inferit.next()
+        next(inferit)
         return # None if there is ambiguity on the inferred node
     except astroid.InferenceError:
         return # there is some kind of ambiguity
@@ -471,7 +471,7 @@ def has_known_bases(klass):
         pass
     try:
         for base in klass.bases:
-            result = base.infer().next()
+            result = next(base.infer())
             # TODO: check for A->B->A->B pattern in class structure too?
             if not isinstance(result, astroid.Class) or result is klass or not has_known_bases(result):
                 klass._all_bases_known = False
diff --git a/checkers/variables.py b/checkers/variables.py
index 71b4be4..6a26f5a 100644
--- a/checkers/variables.py
+++ b/checkers/variables.py
@@ -33,6 +33,7 @@ from pylint.checkers.utils import (
     is_defined_before, is_error, is_func_default, is_func_decorator,
     assign_parent, check_messages, is_inside_except, clobber_in_except,
     get_all_elements, has_known_bases)
+import six
 
 SPECIAL_OBJ = re.compile("^_{2}[a-z]+_{2}$")
 
@@ -45,7 +46,7 @@ def in_for_else_branch(parent, stmt):
 def overridden_method(klass, name):
     """get overridden method if any"""
     try:
-        parent = klass.local_attr_ancestors(name).next()
+        parent = next(klass.local_attr_ancestors(name))
     except (StopIteration, KeyError):
         return None
     try:
@@ -145,7 +146,7 @@ def _fix_dot_imports(not_consumed):
     """
     # TODO: this should be improved in issue astroid #46
     names = {}
-    for name, stmts in not_consumed.iteritems():
+    for name, stmts in six.iteritems(not_consumed):
         if any(isinstance(stmt, astroid.AssName)
                and isinstance(stmt.ass_type(), astroid.AugAssign)
                for stmt in stmts):
@@ -296,7 +297,7 @@ builtins. Remember that you should avoid to define new builtins when possible.'
         checks globals doesn't overrides builtins
         """
         self._to_consume = [(copy(node.locals), {}, 'module')]
-        for name, stmts in node.locals.iteritems():
+        for name, stmts in six.iteritems(node.locals):
             if is_builtin(name) and not is_inside_except(stmts[0]):
                 # do not print Redefining builtin for additional builtins
                 self.add_message('redefined-builtin', args=name, node=stmts[0])
@@ -311,16 +312,16 @@ builtins. Remember that you should avoid to define new builtins when possible.'
         not_consumed = self._to_consume.pop()[0]
         # attempt to check for __all__ if defined
         if '__all__' in node.locals:
-            assigned = node.igetattr('__all__').next()
+            assigned = next(node.igetattr('__all__'))
             if assigned is not astroid.YES:
                 for elt in getattr(assigned, 'elts', ()):
                     try:
-                        elt_name = elt.infer().next()
+                        elt_name = next(elt.infer())
                     except astroid.InferenceError:
                         continue
 
                     if not isinstance(elt_name, astroid.Const) \
-                             or not isinstance(elt_name.value, basestring):
+                             or not isinstance(elt_name.value, six.string_types):
                         self.add_message('invalid-all-object',
                                          args=elt.as_string(), node=elt)
                         continue
@@ -503,7 +504,7 @@ builtins. Remember that you should avoid to define new builtins when possible.'
         for nonlocal_stmt in node.nodes_of_class(astroid.Nonlocal):
             nonlocal_names.update(set(nonlocal_stmt.names))
 
-        for name, stmts in not_consumed.iteritems():
+        for name, stmts in six.iteritems(not_consumed):
             # ignore some special names specified by user configuration
             if authorized_rgx.match(name):
                 continue
@@ -829,7 +830,7 @@ builtins. Remember that you should avoid to define new builtins when possible.'
         for name, _ in node.names:
             parts = name.split('.')
             try:
-                module = node.infer_name_module(parts[0]).next()
+                module = next(node.infer_name_module(parts[0]))
             except astroid.ResolveError:
                 continue
             self._check_module_attrs(node, module, parts[1:])
@@ -916,7 +917,7 @@ builtins. Remember that you should avoid to define new builtins when possible.'
                 module = None
                 break
             try:
-                module = module.getattr(name)[0].infer().next()
+                module = next(module.getattr(name)[0].infer())
                 if module is astroid.YES:
                     return None
             except astroid.NotFoundError:
diff --git a/config.py b/config.py
index c346a0e..942dc21 100644
--- a/config.py
+++ b/config.py
@@ -17,6 +17,7 @@
 * pylint.d (PYLINTHOME)
 """
 from __future__ import with_statement
+from __future__ import print_function
 
 import pickle
 import os
@@ -66,13 +67,13 @@ def save_results(results, base):
         try:
             os.mkdir(PYLINT_HOME)
         except OSError:
-            print >> sys.stderr, 'Unable to create directory %s' % PYLINT_HOME
+            print('Unable to create directory %s' % PYLINT_HOME, file=sys.stderr)
     data_file = get_pdata_path(base, 1)
     try:
         with open(data_file, _PICK_DUMP) as stream:
             pickle.dump(results, stream)
-    except (IOError, OSError), ex:
-        print >> sys.stderr, 'Unable to create file %s: %s' % (data_file, ex)
+    except (IOError, OSError) as ex:
+        print('Unable to create file %s: %s' % (data_file, ex), file=sys.stderr)
 
 # location of the configuration file ##########################################
 
diff --git a/epylint.py b/epylint.py
index beae481..b34ef63 100755
--- a/epylint.py
+++ b/epylint.py
@@ -45,6 +45,7 @@ For example:
 You may also use py_run to run pylint with desired options and get back (or not)
 its output.
 """
+from __future__ import print_function
 
 import sys, os
 import os.path as osp
@@ -102,7 +103,7 @@ def lint(filename, options=None):
         parts = line.split(":")
         if parts and parts[0] == child_path:
             line = ":".join([filename] + parts[1:])
-        print line,
+        print(line, end=' ')
 
     process.wait()
     return process.returncode
@@ -162,10 +163,10 @@ def py_run(command_options='', return_std=False, stdout=None, stderr=None,
 
 def Run():
     if len(sys.argv) == 1:
-        print "Usage: %s <filename> [options]" % sys.argv[0]
+        print("Usage: %s <filename> [options]" % sys.argv[0])
         sys.exit(1)
     elif not osp.exists(sys.argv[1]):
-        print "%s does not exist" % sys.argv[1]
+        print("%s does not exist" % sys.argv[1])
         sys.exit(1)
     else:
         sys.exit(lint(sys.argv[1], sys.argv[2:]))
diff --git a/gui.py b/gui.py
index fcc84e0..bf624b4 100644
--- a/gui.py
+++ b/gui.py
@@ -14,6 +14,7 @@
 # this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 """Tkinker gui for pylint"""
+from __future__ import print_function
 
 import os
 import sys
@@ -86,7 +87,7 @@ class BasicStream(object):
         """finalize what the contents of the dict should look like before output"""
         for item in self.outdict:
             num_empty = self.outdict[item].count('')
-            for _ in xrange(num_empty):
+            for _ in range(num_empty):
                 self.outdict[item].remove('')
             if self.outdict[item]:
                 self.outdict[item].pop(0)
@@ -503,7 +504,7 @@ def lint_thread(module, reporter, gui):
 def Run(args):
     """launch pylint gui from args"""
     if args:
-        print 'USAGE: pylint-gui\n launch a simple pylint gui using Tk'
+        print('USAGE: pylint-gui\n launch a simple pylint gui using Tk')
         sys.exit(1)
     gui = LintGui()
     gui.mainloop()
diff --git a/lint.py b/lint.py
index b258c29..18e37cd 100644
--- a/lint.py
+++ b/lint.py
@@ -60,6 +60,7 @@ from pylint.reporters import initialize as reporters_initialize
 from pylint import config
 
 from pylint.__pkginfo__ import version
+import six
 
 
 
@@ -449,7 +450,7 @@ class PyLinter(OptionsManagerMixIn, MessagesHandlerMixIn, ReportsHandlerMixIn,
         checker.load_defaults()
 
     def disable_noerror_messages(self):
-        for msgcat, msgids in self.msgs_store._msgs_by_category.iteritems():
+        for msgcat, msgids in six.iteritems(self.msgs_store._msgs_by_category):
             if msgcat == 'E':
                 for msgid in msgids:
                     self.enable(msgid)
@@ -459,7 +460,7 @@ class PyLinter(OptionsManagerMixIn, MessagesHandlerMixIn, ReportsHandlerMixIn,
 
     def disable_reporters(self):
         """disable all reporters"""
-        for reporters in self._reports.itervalues():
+        for reporters in six.itervalues(self._reports):
             for report_id, _title, _cb in reporters:
                 self.disable_report(report_id)
 
@@ -524,7 +525,7 @@ class PyLinter(OptionsManagerMixIn, MessagesHandlerMixIn, ReportsHandlerMixIn,
 
     def get_checkers(self):
         """return all available checkers as a list"""
-        return [self] + [c for checkers in self._checkers.itervalues()
+        return [self] + [c for checkers in six.itervalues(self._checkers)
                          for c in checkers if c is not self]
 
     def prepare_checkers(self):
@@ -639,7 +640,7 @@ class PyLinter(OptionsManagerMixIn, MessagesHandlerMixIn, ReportsHandlerMixIn,
         self.current_file = filepath or modname
         self.stats['by_module'][modname] = {}
         self.stats['by_module'][modname]['statement'] = 0
-        for msg_cat in MSG_TYPES.itervalues():
+        for msg_cat in six.itervalues(MSG_TYPES):
             self.stats['by_module'][modname][msg_cat] = 0
 
     def get_ast(self, filepath, modname):
@@ -691,7 +692,7 @@ class PyLinter(OptionsManagerMixIn, MessagesHandlerMixIn, ReportsHandlerMixIn,
         self.stats = {'by_module' : {},
                       'by_msg' : {},
                      }
-        for msg_cat in MSG_TYPES.itervalues():
+        for msg_cat in six.itervalues(MSG_TYPES):
             self.stats[msg_cat] = 0
 
     def close(self):
@@ -764,7 +765,7 @@ def report_messages_stats(sect, stats, _):
         # don't print this report when we didn't detected any errors
         raise EmptyReport()
     in_order = sorted([(value, msg_id)
-                       for msg_id, value in stats['by_msg'].iteritems()
+                       for msg_id, value in six.iteritems(stats['by_msg'])
                        if not msg_id.startswith('I')])
     in_order.reverse()
     lines = ('message id', 'occurrences')
@@ -780,7 +781,7 @@ def report_messages_by_module_stats(sect, stats, _):
     by_mod = {}
     for m_type in ('fatal', 'error', 'warning', 'refactor', 'convention'):
         total = stats[m_type]
-        for module in stats['by_module'].iterkeys():
+        for module in six.iterkeys(stats['by_module']):
             mod_total = stats['by_module'][module][m_type]
             if total == 0:
                 percent = 0
@@ -788,7 +789,7 @@ def report_messages_by_module_stats(sect, stats, _):
                 percent = float((mod_total)*100) / total
             by_mod.setdefault(module, {})[m_type] = percent
     sorted_result = []
-    for module, mod_info in by_mod.iteritems():
+    for module, mod_info in six.iteritems(by_mod):
         sorted_result.append((mod_info['error'],
                               mod_info['warning'],
                               mod_info['refactor'],
@@ -1077,7 +1078,7 @@ group are mutually exclusive.'),
 
 def cb_init_hook(optname, value):
     """exec arbitrary code to set sys.path for instance"""
-    exec value
+    exec(value)
 
 
 if __name__ == '__main__':
diff --git a/pyreverse/diadefslib.py b/pyreverse/diadefslib.py
index 46d0f19..0b42065 100644
--- a/pyreverse/diadefslib.py
+++ b/pyreverse/diadefslib.py
@@ -99,8 +99,8 @@ class DiaDefGenerator(object):
         """return associated nodes of a class node"""
         if level == 0:
             return
-        for ass_nodes in klass_node.instance_attrs_type.values() + \
-                         klass_node.locals_type.values():
+        for ass_nodes in list(klass_node.instance_attrs_type.values()) + \
+                         list(klass_node.locals_type.values()):
             for ass_node in ass_nodes:
                 if isinstance(ass_node, astroid.Instance):
                     ass_node = ass_node._proxied
@@ -198,7 +198,7 @@ class ClassDiadefGenerator(DiaDefGenerator):
         else:
             module = project.modules[0]
             klass = klass.split('.')[-1]
-        klass = module.ilookup(klass).next()
+        klass = next(module.ilookup(klass))
 
         anc_level, ass_level = self._get_levels()
         self.extract_classes(klass, anc_level, ass_level)
diff --git a/pyreverse/diagrams.py b/pyreverse/diagrams.py
index 28cc500..f0d7a92 100644
--- a/pyreverse/diagrams.py
+++ b/pyreverse/diagrams.py
@@ -77,8 +77,8 @@ class ClassDiagram(Figure, FilterMixIn):
     def get_attrs(self, node):
         """return visible attributes, possibly with class name"""
         attrs = []
-        for node_name, ass_nodes in node.instance_attrs_type.items() + \
-                                node.locals_type.items():
+        for node_name, ass_nodes in list(node.instance_attrs_type.items()) + \
+                                list(node.locals_type.items()):
             if not self.show_attr(node_name):
                 continue
             names = self.class_names(ass_nodes)
@@ -170,8 +170,8 @@ class ClassDiagram(Figure, FilterMixIn):
                 except KeyError:
                     continue
             # associations link
-            for name, values in node.instance_attrs_type.items() + \
-                                node.locals_type.items():
+            for name, values in list(node.instance_attrs_type.items()) + \
+                                list(node.locals_type.items()):
                 for value in values:
                     if value is astroid.YES:
                         continue
diff --git a/pyreverse/main.py b/pyreverse/main.py
index d4991b5..408c172 100644
--- a/pyreverse/main.py
+++ b/pyreverse/main.py
@@ -18,6 +18,7 @@
 
   create UML diagrams for classes and modules in <packages>
 """
+from __future__ import print_function
 
 import sys, os
 from logilab.common.configuration import ConfigurationMixIn
@@ -99,7 +100,7 @@ class Run(ConfigurationMixIn):
     def run(self, args):
         """checking arguments and run project"""
         if not args:
-            print self.help()
+            print(self.help())
             return 1
         # insert current working directory to the python path to recognize
         # dependencies to local modules even if cwd is not in the PYTHONPATH
diff --git a/pyreverse/utils.py b/pyreverse/utils.py
index 3d12d41..58559d7 100644
--- a/pyreverse/utils.py
+++ b/pyreverse/utils.py
@@ -16,6 +16,7 @@
 """
 generic classes/functions for pyreverse core/extensions
 """
+from __future__ import print_function
 
 import sys
 import re
@@ -118,8 +119,8 @@ class FilterMixIn(object):
         for nummod in mode.split('+'):
             try:
                 __mode += MODES[nummod]
-            except KeyError, ex:
-                print >> sys.stderr, 'Unknown filter mode %s' % ex
+            except KeyError as ex:
+                print('Unknown filter mode %s' % ex, file=sys.stderr)
         self.__mode = __mode
 
 
diff --git a/reporters/__init__.py b/reporters/__init__.py
index 429155a..8be5d3a 100644
--- a/reporters/__init__.py
+++ b/reporters/__init__.py
@@ -12,6 +12,7 @@
 # this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 """utilities methods and classes for reporters"""
+from __future__ import print_function
 
 import sys
 import locale
@@ -90,7 +91,7 @@ class BaseReporter(object):
 
     def writeln(self, string=''):
         """write a line in the output buffer"""
-        print >> self.out, self.encode(string)
+        print(self.encode(string), file=self.out)
 
     def display_results(self, layout):
         """display results encapsulated in the layout tree"""
diff --git a/reporters/text.py b/reporters/text.py
index 48b5155..acb22b5 100644
--- a/reporters/text.py
+++ b/reporters/text.py
@@ -16,6 +16,7 @@
 :text: the default one grouping messages by module
 :colorized: an ANSI colorized text reporter
 """
+from __future__ import print_function
 
 import warnings
 
@@ -24,6 +25,7 @@ from logilab.common.textutils import colorize_ansi
 
 from pylint.interfaces import IReporter
 from pylint.reporters import BaseReporter
+import six
 
 TITLE_UNDERLINES = ['', '=', '-', '.']
 
@@ -42,7 +44,7 @@ class TextReporter(BaseReporter):
         self._template = None
 
     def on_set_current_module(self, module, filepath):
-        self._template = unicode(self.linter.config.msg_template or self.line_format)
+        self._template = six.text_type(self.linter.config.msg_template or self.line_format)
 
     def write_message(self, msg):
         """Convenience method to write a formated message with class default template"""
@@ -60,7 +62,7 @@ class TextReporter(BaseReporter):
 
     def _display(self, layout):
         """launch layouts display"""
-        print >> self.out
+        print(file=self.out)
         TextWriter().format(layout, self.out)
 
 
diff --git a/setup.py b/setup.py
index 45b76be..28b7d3e 100644
--- a/setup.py
+++ b/setup.py
@@ -20,6 +20,7 @@
 # with pylint.  If not, see <http://www.gnu.org/licenses/>.
 """Generic Setup script, takes package info from __pkginfo__.py file.
 """
+from __future__ import absolute_import, print_function
 __docformat__ = "restructuredtext en"
 
 import os
@@ -38,14 +39,7 @@ except ImportError:
     from distutils.command import install_lib
     USE_SETUPTOOLS = 0
 
-try:
-    # pylint: disable=no-name-in-module
-    # python3
-    from distutils.command.build_py import build_py_2to3 as build_py
-except ImportError:
-    # pylint: disable=no-name-in-module
-    # python2.x
-    from distutils.command.build_py import build_py
+from distutils.command.build_py import build_py
 
 sys.modules.pop('__pkginfo__', None)
 # import optional features
@@ -144,7 +138,7 @@ class MyInstallLib(install_lib.install_lib):
                     # process manually python file in include_dirs (test data)
                     # pylint: disable=no-name-in-module
                     from distutils.util import run_2to3
-                    print('running 2to3 on', dest)
+                    print(('running 2to3 on', dest))
                     run_2to3([dest])
 
     # override this since pip/easy_install attempt to byte compile test data
diff --git a/testutils.py b/testutils.py
index 86539ac..a059fe4 100644
--- a/testutils.py
+++ b/testutils.py
@@ -14,11 +14,11 @@
 # this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 """functional/non regression tests for pylint"""
+from __future__ import print_function
 
 import collections
 import contextlib
 import functools
-import cStringIO
 import sys
 import re
 import unittest
@@ -35,6 +35,9 @@ from pylint.reporters import BaseReporter
 from pylint.interfaces import IReporter
 from pylint.lint import PyLinter
 
+import six
+from six.moves import StringIO
+
 
 # Utils
 
@@ -94,7 +97,7 @@ class TestReporter(BaseReporter):
         self.reset()
 
     def reset(self):
-        self.out = cStringIO.StringIO()
+        self.out = StringIO()
         self.messages = []
 
     def add_message(self, msg_id, location, msg):
@@ -113,7 +116,7 @@ class TestReporter(BaseReporter):
     def finalize(self):
         self.messages.sort()
         for msg in self.messages:
-            print >> self.out, msg
+            print(msg, file=self.out)
         result = self.out.getvalue()
         self.reset()
         return result
@@ -148,7 +151,7 @@ class UnittestLinter(object):
         return True
 
     def add_stats(self, **kwargs):
-        for name, value in kwargs.iteritems():
+        for name, value in six.iteritems(kwargs):
             self.stats[name] = value
         return self.stats
 
@@ -161,7 +164,7 @@ def set_config(**kwargs):
     def _Wrapper(fun):
         @functools.wraps(fun)
         def _Forward(self):
-            for key, value in kwargs.iteritems():
+            for key, value in six.iteritems(kwargs):
                 setattr(self.checker.config, key, value)
             if isinstance(self, CheckerTestCase):
                 # reopen checker in case, it may be interested in configuration change
@@ -180,7 +183,7 @@ class CheckerTestCase(unittest.TestCase):
     def setUp(self):
         self.linter = UnittestLinter()
         self.checker = self.CHECKER_CLASS(self.linter) # pylint: disable=not-callable
-        for key, value in self.CONFIG.iteritems():
+        for key, value in six.iteritems(self.CONFIG):
             setattr(self.checker.config, key, value)
         self.checker.open()
 
@@ -277,11 +280,11 @@ class LintTestUsingModule(unittest.TestCase):
             self.linter.disable('I')
         try:
             self.linter.check(tocheck)
-        except Exception, ex:
+        except Exception as ex:
             # need finalization to restore a correct state
             self.linter.reporter.finalize()
             ex.file = tocheck
-            print ex
+            print(ex)
             ex.__str__ = exception_str
             raise
         self._check_result(self.linter.reporter.finalize())
diff --git a/tox.ini b/tox.ini
index 480ae76..5b3ec53 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,5 +6,6 @@ envlist = py27, py33
 deps =
   logilab-common
   hg+https://bitbucket.org/logilab/astroid/
+  six
 commands = python -Wi -m unittest discover -s {envsitepackagesdir}/pylint/test/ -p {posargs:*test_*}.py
 changedir = {toxworkdir}
diff --git a/utils.py b/utils.py
index ef4bf44..068afce 100644
--- a/utils.py
+++ b/utils.py
@@ -37,6 +37,8 @@ from astroid.modutils import modpath_from_file, get_module_files, \
     file_from_modpath, load_module_from_file
 
 from pylint.interfaces import IRawChecker, ITokenChecker, UNDEFINED
+import six
+from six.moves import zip
 
 
 class UnknownMessage(Exception):
@@ -54,7 +56,7 @@ MSG_TYPES = {
     'E' : 'error',
     'F' : 'fatal'
     }
-MSG_TYPES_LONG = {v: k for k, v in MSG_TYPES.iteritems()}
+MSG_TYPES_LONG = {v: k for k, v in six.iteritems(MSG_TYPES)}
 
 MSG_TYPES_STATUS = {
     'I' : 0,
@@ -265,7 +267,7 @@ class MessagesHandlerMixIn(object):
             msgs = self._msgs_state
             msgs[msg.msgid] = False
             # sync configuration object
-            self.config.disable_msg = [mid for mid, val in msgs.iteritems()
+            self.config.disable_msg = [mid for mid, val in six.iteritems(msgs)
                                        if not val]
 
     def enable(self, msgid, scope='package', line=None, ignore_unknown=False):
@@ -303,7 +305,7 @@ class MessagesHandlerMixIn(object):
             msgs = self._msgs_state
             msgs[msg.msgid] = True
             # sync configuration object
-            self.config.enable = [mid for mid, val in msgs.iteritems() if val]
+            self.config.enable = [mid for mid, val in six.iteritems(msgs) if val]
 
     def get_message_state_scope(self, msgid, line=None, confidence=UNDEFINED):
         """Returns the scope at which a message was enabled/disabled."""
@@ -425,7 +427,7 @@ class MessagesHandlerMixIn(object):
                     by_checker[checker.name] = [list(checker.options_and_values()),
                                                 dict(checker.msgs),
                                                 list(checker.reports)]
-        for checker, (options, msgs, reports) in by_checker.iteritems():
+        for checker, (options, msgs, reports) in six.iteritems(by_checker):
             prefix = ''
             title = '%s checker' % checker
             print(title)
@@ -441,7 +443,7 @@ class MessagesHandlerMixIn(object):
                 title = ('%smessages' % prefix).capitalize()
                 print(title)
                 print('~' * len(title))
-                for msgid, msg in sorted(msgs.iteritems(),
+                for msgid, msg in sorted(six.iteritems(msgs),
                                          key=lambda kv: (_MSG_ORDER.index(kv[0][0]), kv[1])):
                     msg = build_message_def(checker, msgid, msg)
                     print(msg.format_help(checkerref=False))
@@ -468,7 +470,7 @@ class FileState(object):
 
     def collect_block_lines(self, msgs_store, module_node):
         """Walk the AST to collect block level options line numbers."""
-        for msg, lines in self._module_msgs_state.iteritems():
+        for msg, lines in six.iteritems(self._module_msgs_state):
             self._raw_module_msgs_state[msg] = lines.copy()
         orig_state = self._module_msgs_state.copy()
         self._module_msgs_state = {}
@@ -502,8 +504,8 @@ class FileState(object):
             firstchildlineno = node.body[0].fromlineno
         else:
             firstchildlineno = last
-        for msgid, lines in msg_state.iteritems():
-            for lineno, state in lines.items():
+        for msgid, lines in six.iteritems(msg_state):
+            for lineno, state in list(lines.items()):
                 original_lineno = lineno
                 if first <= lineno <= last:
                     # Set state for all lines for this block, if the
@@ -515,7 +517,7 @@ class FileState(object):
                     else:
                         first_ = lineno
                         last_ = last
-                    for line in xrange(first_, last_+1):
+                    for line in range(first_, last_+1):
                         # do not override existing entries
                         if not line in self._module_msgs_state.get(msgid, ()):
                             if line in lines: # state change in the same block
@@ -552,13 +554,13 @@ class FileState(object):
                 pass
 
     def iter_spurious_suppression_messages(self, msgs_store):
-        for warning, lines in self._raw_module_msgs_state.iteritems():
-            for line, enable in lines.iteritems():
+        for warning, lines in six.iteritems(self._raw_module_msgs_state):
+            for line, enable in six.iteritems(lines):
                 if not enable and (warning, line) not in self._ignored_msgs:
                     yield 'useless-suppression', line, \
                         (msgs_store.get_msg_display_string(warning),)
         # don't use iteritems here, _ignored_msgs may be modified by add_message
-        for (warning, from_), lines in self._ignored_msgs.items():
+        for (warning, from_), lines in list(self._ignored_msgs.items()):
             for line in lines:
                 yield 'suppressed-message', line, \
                     (msgs_store.get_msg_display_string(warning), from_)
@@ -584,7 +586,7 @@ class MessagesStore(object):
     @property
     def messages(self):
         """The list of all active messages."""
-        return self._messages.itervalues()
+        return six.itervalues(self._messages)
 
     def add_renamed_message(self, old_id, old_symbol, new_symbol):
         """Register the old ID and symbol for a warning that was renamed.
@@ -606,7 +608,7 @@ class MessagesStore(object):
         are the checker id and the two last the message id in this checker
         """
         chkid = None
-        for msgid, msg_tuple in checker.msgs.iteritems():
+        for msgid, msg_tuple in six.iteritems(checker.msgs):
             msg = build_message_def(checker, msgid, msg_tuple)
             assert msg.symbol not in self._messages, \
                     'Message symbol %r is already defined' % msg.symbol
@@ -659,7 +661,7 @@ class MessagesStore(object):
 
     def list_messages(self):
         """output full messages list documentation in ReST format"""
-        msgs = sorted(self._messages.itervalues(), key=lambda msg: msg.msgid)
+        msgs = sorted(six.itervalues(self._messages), key=lambda msg: msg.msgid)
         for msg in msgs:
             if not msg.may_be_emitted():
                 continue
@@ -729,7 +731,7 @@ class ReportsHandlerMixIn(object):
         """add some stats entries to the statistic dictionary
         raise an AssertionError if there is a key conflict
         """
-        for key, value in kwargs.iteritems():
+        for key, value in six.iteritems(kwargs):
             if key[-1] == '_':
                 key = key[:-1]
             assert key not in self.stats
@@ -866,7 +868,8 @@ def register_plugins(linter, directory):
                 # empty module name (usually emacs auto-save files)
                 continue
             except ImportError as exc:
-                print >> sys.stderr, "Problem importing module %s: %s" % (filename, exc)
+                print("Problem importing module %s: %s" % (filename, exc),
+                      file=sys.stderr)
             else:
                 if hasattr(module, 'register'):
                     module.register(linter)