Drop support for Python 2.6

I would humbly like to suggest dateutil drop support for Python 2.6.

The last release of Python 2.6 was 2013-10-29, over 3 years ago. It is
no longer receiving security fixes.

https://www.python.org/dev/peps/pep-0361/

The pip project itself has recently dropped support for 2.6. Their
numbers estimate that Python 2.6 accounts for ~2% of their downloads.

pypa/pip#4343

For projects that still use Python 2.6, they can continue to pip install
an older version.

I've tried my best to remove as much 2.6 specific code as I can,
including the 'Programming Language :: Python :: 2.6' trove classifier
from setup.py. I've also removed Travis CI testing, which should result
in faster testing and fewer wasted resources.

Code changed:

- Removed Python2.6 from testing configuration
- setup.py cleanups due to fewer version complications
- Removed unittest2 dependency and monkey patching
- Use set literals
- Use dict comprehension
- Remove total_seconds workaround
- Remove TarFile.open() context manager workaround

Thanks for considering.

.travis.yml

@@ -1,7 +1,6 @@
 language: python
 cache: pip
 python:
-  - "2.6"
   - "2.7"
   - "3.2"
   - "3.3"
@@ -25,7 +24,6 @@ before_install:
 
 install:
   - pip install six
-  - if [[ $TRAVIS_PYTHON_VERSION == '2.6' ]]; then pip install unittest2; fi
   - ./ci_tools/retry.sh python updatezinfo.py
 
 script:

NEWS

@@ -1,3 +1,7 @@
+UNRELEASED
+----------
+- **Dropped support for Python 2.6.**
+
 Version 2.6.1
 -------------
 - Updated zoneinfo file to 2017b. (gh pr #395)

dateutil/parser.py

@@ -677,7 +677,7 @@ def _parse(self, timestr, dayfirst=None, yearfirst=None, fuzzy=False,
         # keep up with the last token skipped so we can recombine
         # consecutively skipped tokens (-2 for when i begins at 0).
         last_skipped_token_i = -2
-        skipped_tokens = list()
+        skipped_tokens = []
 
         try:
             # year/month/day list

dateutil/rrule.py

@@ -584,13 +584,13 @@ def __init__(self, freq, dtstart=None,
                 self._byweekday = tuple(sorted(self._byweekday))
                 orig_byweekday = [weekday(x) for x in self._byweekday]
             else:
-                orig_byweekday = tuple()
+                orig_byweekday = ()
 
             if self._bynweekday is not None:
                 self._bynweekday = tuple(sorted(self._bynweekday))
                 orig_bynweekday = [weekday(*x) for x in self._bynweekday]
             else:
-                orig_bynweekday = tuple()
+                orig_bynweekday = ()
 
             if 'byweekday' not in self._original_rule:
                 self._original_rule['byweekday'] = tuple(itertools.chain(
@@ -599,7 +599,7 @@ def __init__(self, freq, dtstart=None,
         # byhour
         if byhour is None:
             if freq < HOURLY:
-                self._byhour = set((dtstart.hour,))
+                self._byhour = {dtstart.hour}
             else:
                 self._byhour = None
         else:
@@ -619,7 +619,7 @@ def __init__(self, freq, dtstart=None,
         # byminute
         if byminute is None:
             if freq < MINUTELY:
-                self._byminute = set((dtstart.minute,))
+                self._byminute = {dtstart.minute}
             else:
                 self._byminute = None
         else:

dateutil/test/_common.py

@@ -1,9 +1,4 @@
 from __future__ import unicode_literals
-try:
-    import unittest2 as unittest
-except ImportError:
-    import unittest
-
 import os
 import datetime
 import time
@@ -209,18 +204,6 @@ def set_current_tz(self, tzname):
                           (err or 'Unknown error.'))
 
 
-###
-# Compatibility functions
-
-def _total_seconds(td):
-    # Python 2.6 doesn't have a total_seconds() method on timedelta objects
-    return ((td.seconds + td.days * 86400) * 1000000 +
-            td.microseconds) // 1000000
-
-
-total_seconds = getattr(datetime.timedelta, 'total_seconds', _total_seconds)
-
-
 ###
 # Utility classes
 class NotAValueClass(object):

dateutil/test/test_easter.py

@@ -2,11 +2,7 @@
 from dateutil.easter import EASTER_WESTERN, EASTER_ORTHODOX, EASTER_JULIAN
 
 from datetime import date
-
-try:
-    import unittest2 as unittest
-except ImportError:
-    import unittest
+import unittest
 
 # List of easters between 1990 and 2050
 western_easter_dates = [

dateutil/test/test_imports.py

@@ -1,9 +1,5 @@
 import sys
-
-try:
-    import unittest2 as unittest
-except ImportError:
-    import unittest
+import unittest
 
 class ImportVersionTest(unittest.TestCase):
     """ Test that dateutil.__version__ can be imported"""

dateutil/test/test_parser.py

@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
-from ._common import unittest
 
 from datetime import datetime, timedelta
+import unittest
 
 from dateutil.tz import tzoffset
 from dateutil.parser import parse, parserinfo

dateutil/test/test_relativedelta.py

@@ -1,9 +1,10 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
-from ._common import unittest, WarningTestMixin, NotAValue
+from ._common import WarningTestMixin, NotAValue
 
 import calendar
 from datetime import datetime, date, timedelta
+import unittest
 
 from dateutil.relativedelta import relativedelta, MO, TU, WE, FR, SU
 

dateutil/test/test_rrule.py

@@ -1,8 +1,9 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
-from ._common import WarningTestMixin, unittest
+from ._common import WarningTestMixin
 
 from datetime import datetime, date
+import unittest
 from six import PY3
 
 from dateutil.rrule import (

dateutil/test/test_tz.py

@@ -1,7 +1,6 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
-from ._common import unittest, PicklableMixin
-from ._common import total_seconds
+from ._common import PicklableMixin
 from ._common import TZEnvContext, TZWinContext
 from ._common import WarningTestMixin
 from ._common import ComparesEqual
@@ -10,6 +9,7 @@
 from datetime import time as dt_time
 from datetime import tzinfo
 from six import BytesIO, StringIO
+import unittest
 
 import sys
 import base64
@@ -280,7 +280,7 @@ def testFoldLondon(self):
 
             self.assertEqual(t0.replace(tzinfo=None),
                              datetime(2013, 10, 27, 1, 30))
-            
+
             self.assertEqual(t1.replace(tzinfo=None),
                              datetime(2013, 10, 27, 1, 30))
 
@@ -317,14 +317,14 @@ def testFoldIndependence(self):
 
     def testInZoneFoldEquality(self):
         # Two datetimes in the same zone are considered to be equal if their
-        # wall times are equal, even if they have different absolute times. 
+        # wall times are equal, even if they have different absolute times.
 
         tzname = self._get_tzname('America/New_York')
 
         with self._gettz_context(tzname):
             NYC = self.gettz(tzname)
             UTC = tz.tzutc()
-            
+
             dt0 = datetime(2011, 11, 6, 1, 30, tzinfo=NYC)
             dt1 = tz.enfold(dt0, fold=1)
 
@@ -574,7 +574,7 @@ def testFoldIndependence(self):
 
     def testInZoneFoldEquality(self):
         # Two datetimes in the same zone are considered to be equal if their
-        # wall times are equal, even if they have different absolute times. 
+        # wall times are equal, even if they have different absolute times.
         tzname = 'Eastern Standard Time'
         args = self.get_args(tzname)
 
@@ -583,7 +583,7 @@ def testInZoneFoldEquality(self):
             UTC = tz.tzutc()
 
             t_n, t0_u, t1_u = self.get_utc_transitions(NYC, 2011, False)
-            
+
             dt0 = t_n.replace(tzinfo=NYC)
             dt1 = tz.enfold(dt0, fold=1)
 
@@ -714,8 +714,8 @@ def testEquality(self):
 
     def testInequalityFixedOffset(self):
         tzl = tz.tzlocal()
-        tzos = tz.tzoffset('LST', total_seconds(tzl._std_offset))
-        tzod = tz.tzoffset('LDT', total_seconds(tzl._std_offset))
+        tzos = tz.tzoffset('LST', tzl._std_offset.total_seconds())
+        tzod = tz.tzoffset('LDT', tzl._std_offset.total_seconds())
 
         self.assertFalse(tzl == tzos)
         self.assertFalse(tzl == tzod)
@@ -1745,7 +1745,7 @@ def setUp(self):
         self.context = TZWinContext
 
     def get_args(self, tzname):
-        return tuple()
+        return ()
 
     def testLocal(self):
         # Not sure how to pin a local time zone, so for now we're just going

dateutil/tz/_common.py

@@ -383,12 +383,3 @@ def __repr__(self):
         return "%s(...)" % self.__class__.__name__
 
     __reduce__ = object.__reduce__
-
-
-def _total_seconds(td):
-    # Python 2.6 doesn't have a total_seconds() method on timedelta objects
-    return ((td.seconds + td.days * 86400) * 1000000 +
-            td.microseconds) // 1000000
-
-
-_total_seconds = getattr(timedelta, 'total_seconds', _total_seconds)

dateutil/tz/tz.py

@@ -15,7 +15,7 @@
 import bisect
 
 from six import string_types
-from ._common import tzname_in_python2, _tzinfo, _total_seconds
+from ._common import tzname_in_python2, _tzinfo
 from ._common import tzrangebase, enfold
 from ._common import _validate_fromutc_inputs
 
@@ -101,7 +101,7 @@ def __init__(self, name, offset):
 
         try:
             # Allow a timedelta
-            offset = _total_seconds(offset)
+            offset = offset.total_seconds()
         except (TypeError, AttributeError):
             pass
         self._offset = datetime.timedelta(seconds=offset)
@@ -150,7 +150,7 @@ def __ne__(self, other):
     def __repr__(self):
         return "%s(%s, %s)" % (self.__class__.__name__,
                                repr(self._name),
-                               int(_total_seconds(self._offset)))
+                               int(self._offset.total_seconds()))
 
     __reduce__ = object.__reduce__
 
@@ -616,7 +616,7 @@ def _find_last_transition(self, dt, in_utc=False):
         idx = bisect.bisect_right(trans_list, timestamp)
 
         # We want to know when the previous transition was, so subtract off 1
-        return idx - 1        
+        return idx - 1
 
     def _get_ttinfo(self, idx):
         # For no list or after the last transition, default to _ttinfo_std
@@ -850,12 +850,12 @@ def __init__(self, stdabbr, stdoffset=None,
         self._dst_abbr = dstabbr
 
         try:
-            stdoffset = _total_seconds(stdoffset)
+            stdoffset = stdoffset.total_seconds()
         except (TypeError, AttributeError):
             pass
 
         try:
-            dstoffset = _total_seconds(dstoffset)
+            dstoffset = dstoffset.total_seconds()
         except (TypeError, AttributeError):
             pass
 
@@ -1491,7 +1491,7 @@ def _datetime_to_timestamp(dt):
     Convert a :class:`datetime.datetime` object to an epoch timestamp in seconds
     since January 1, 1970, ignoring the time zone.
     """
-    return _total_seconds((dt.replace(tzinfo=None) - EPOCH))
+    return (dt.replace(tzinfo=None) - EPOCH).total_seconds()
 
 
 class _ContextWrapper(object):

dateutil/tz/win.py

@@ -192,7 +192,6 @@ class tzwin(tzwinbase):
     def __init__(self, name):
         self._name = name
 
-        # multiple contexts only possible in 2.7 and 3.1, we still support 2.6
         with winreg.ConnectRegistry(None, winreg.HKEY_LOCAL_MACHINE) as handle:
             tzkeyname = text_type("{kn}\\{name}").format(kn=TZKEYNAME, name=name)
             with winreg.OpenKey(handle, tzkeyname) as tzkey:

dateutil/zoneinfo/__init__.py

@@ -14,13 +14,6 @@
 ZONEFILENAME = "dateutil-zoneinfo.tar.gz"
 METADATA_FN = 'METADATA'
 
-# python2.6 compatability. Note that TarFile.__exit__ != TarFile.close, but
-# it's close enough for python2.6
-tar_open = TarFile.open
-if not hasattr(TarFile, '__exit__'):
-    def tar_open(*args, **kwargs):
-        return closing(TarFile.open(*args, **kwargs))
-
 
 class tzfile(tzfile):
     def __reduce__(self):
@@ -38,23 +31,15 @@ def getzoneinfofile_stream():
 class ZoneInfoFile(object):
     def __init__(self, zonefile_stream=None):
         if zonefile_stream is not None:
-            with tar_open(fileobj=zonefile_stream, mode='r') as tf:
-                # dict comprehension does not work on python2.6
-                # TODO: get back to the nicer syntax when we ditch python2.6
-                # self.zones = {zf.name: tzfile(tf.extractfile(zf),
-                #               filename = zf.name)
-                #              for zf in tf.getmembers() if zf.isfile()}
-                self.zones = dict((zf.name, tzfile(tf.extractfile(zf),
-                                                   filename=zf.name))
-                                  for zf in tf.getmembers()
-                                  if zf.isfile() and zf.name != METADATA_FN)
+            with TarFile.open(fileobj=zonefile_stream) as tf:
+                self.zones = {zf.name: tzfile(tf.extractfile(zf), filename=zf.name)
+                              for zf in tf.getmembers()
+                              if zf.isfile() and zf.name != METADATA_FN}
                 # deal with links: They'll point to their parent object. Less
                 # waste of memory
-                # links = {zl.name: self.zones[zl.linkname]
-                #        for zl in tf.getmembers() if zl.islnk() or zl.issym()}
-                links = dict((zl.name, self.zones[zl.linkname])
-                             for zl in tf.getmembers() if
-                             zl.islnk() or zl.issym())
+                links = {zl.name: self.zones[zl.linkname]
+                         for zl in tf.getmembers() if
+                         zl.islnk() or zl.issym()}
                 self.zones.update(links)
                 try:
                     metadata_json = tf.extractfile(tf.getmember(METADATA_FN))
@@ -64,7 +49,7 @@ def __init__(self, zonefile_stream=None):
                     # no metadata in tar file
                     self.metadata = None
         else:
-            self.zones = dict()
+            self.zones = {}
             self.metadata = None
 
     def get(self, name, default=None):
@@ -90,7 +75,7 @@ def get(self, name, default=None):
 # timezone. Ugly, but adheres to the api.
 #
 # TODO: Remove after deprecation period.
-_CLASS_ZONE_INSTANCE = list()
+_CLASS_ZONE_INSTANCE = []
 
 
 def get_zonefile_instance(new_instance=False):