Use tz.gettz() instead of zoneinfo.gettz()

zoneinfo.gettz() seems to have problems (1 & 2) on system which do not install
the zoninfo tarball (e.g. Debian, Gentoo and Fedora) but rely on the system
zoneinfo files. This results in test failures (3 & 4)
tz.gettz() doesn't suffer from this problem.

1 dateutil/dateutil#8
2 dateutil/dateutil#11
3 pandas-dev#9059
4 pandas-dev#8639

Signed-off-by: Justin Lecher <jlec@gentoo.org>

pandas/tests/test_series.py

@@ -5021,7 +5021,7 @@ def test_getitem_setitem_datetime_tz_pytz(self):
     def test_getitem_setitem_datetime_tz_dateutil(self):
         tm._skip_if_no_dateutil();
         from dateutil.tz import tzutc
-        from dateutil.zoneinfo import gettz
+        from dateutil.tz import gettz
         tz = lambda x: tzutc() if x == 'UTC' else gettz(x)  # handle special case for utc in dateutil
 
         from pandas import date_range

pandas/tseries/tests/test_daterange.py

@@ -441,7 +441,7 @@ def test_month_range_union_tz_pytz(self):
     def test_month_range_union_tz_dateutil(self):
         _skip_if_windows_python_3()
         tm._skip_if_no_dateutil()
-        from dateutil.zoneinfo import gettz as timezone
+        from dateutil.tz import gettz as timezone
         tz = timezone('US/Eastern')
 
         early_start = datetime(2011, 1, 1)

pandas/tseries/tests/test_period.py

@@ -104,12 +104,12 @@ def test_timestamp_tz_arg_dateutil(self):
         import dateutil
         from pandas.tslib import maybe_get_tz
         p = Period('1/1/2005', freq='M').to_timestamp(tz=maybe_get_tz('dateutil/Europe/Brussels'))
-        self.assertEqual(p.tz, dateutil.zoneinfo.gettz('Europe/Brussels'))
+        self.assertEqual(p.tz, dateutil.tz.gettz('Europe/Brussels'))
 
     def test_timestamp_tz_arg_dateutil_from_string(self):
         import dateutil
         p = Period('1/1/2005', freq='M').to_timestamp(tz='dateutil/Europe/Brussels')
-        self.assertEqual(p.tz, dateutil.zoneinfo.gettz('Europe/Brussels'))
+        self.assertEqual(p.tz, dateutil.tz.gettz('Europe/Brussels'))
 
     def test_timestamp_nat_tz(self):
         t = Period('NaT', freq='M').to_timestamp()

pandas/tseries/tests/test_timeseries.py

@@ -419,7 +419,7 @@ def test_timestamp_to_datetime_explicit_dateutil(self):
         tm._skip_if_no_dateutil()
         import dateutil
         rng = date_range('20090415', '20090519',
-                         tz=dateutil.zoneinfo.gettz('US/Eastern'))
+                         tz=dateutil.tz.gettz('US/Eastern'))
 
         stamp = rng[0]
         dtval = stamp.to_pydatetime()
@@ -1797,7 +1797,7 @@ def test_append_concat_tz_explicit_pytz(self):
     def test_append_concat_tz_dateutil(self):
         # GH 2938
         tm._skip_if_no_dateutil()
-        from dateutil.zoneinfo import gettz as timezone
+        from dateutil.tz import gettz as timezone
 
         rng = date_range('5/8/2012 1:45', periods=10, freq='5T',
                          tz='dateutil/US/Eastern')

pandas/tslib.pyx

@@ -41,7 +41,7 @@ from datetime import time as datetime_time
 # dateutil compat
 from dateutil.tz import (tzoffset, tzlocal as _dateutil_tzlocal, tzfile as _dateutil_tzfile,
                          tzutc as _dateutil_tzutc)
-from dateutil.zoneinfo import gettz as _dateutil_gettz
+from dateutil.tz import gettz as _dateutil_gettz
 
 from pytz.tzinfo import BaseTzInfo as _pytz_BaseTzInfo
 from pandas.compat import parse_date, string_types, PY3, iteritems