Merge pull request #157 from ocefpaf/drop_py2k

drop python 2

.travis.yml

@@ -1,7 +1,6 @@
 language: minimal
 
 env:
-  - PYTHON_VERSION=2.7
   - PYTHON_VERSION=3.6
   - PYTHON_VERSION=3.7
   - PYTHON_VERSION=3.8

cf_units/__init__.py

@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2015 - 2019, Met Office
+# (C) British Crown Copyright 2015 - 2020, Met Office
 #
 # This file is part of cf-units.
 #
@@ -25,11 +25,6 @@
 
 """
 
-from __future__ import (absolute_import, division, print_function)
-from six.moves import (filter, input, map, range, zip)  # noqa
-
-import six
-
 from contextlib import contextmanager
 import copy
 import os.path
@@ -630,7 +625,7 @@ def as_unit(unit):
         result = unit
     else:
         result = None
-        use_cache = isinstance(unit, six.string_types) or unit is None
+        use_cache = isinstance(unit, (str,)) or unit is None
         if use_cache:
             result = _CACHE.get(unit)
         if result is None:
@@ -703,8 +698,6 @@ def _ud_value_error(ud_err, message):
     message = u'[{status}] {message}'.format(
         status=ud_err.status_msg(), message=message)
 
-    if six.PY2:
-        message = message.encode('utf8')
     return ValueError(message)
 
 
@@ -829,16 +822,7 @@ def __init__(self, unit, calendar=None):
         if unit is None:
             unit = ''
 
-        if six.PY2:
-            if not isinstance(unit, six.text_type):
-                # Cast everything that isn't a unicode object to a str.
-                unit = str(unit)
-            if isinstance(unit, str):
-                # All str in py2 should be treated as ASCII.
-                encoding = UT_ASCII
-        else:
-            unit = str(unit)
-        unit = unit.strip()
+        unit = str(unit).strip()
 
         if unit.lower().endswith(' utc'):
             unit = unit[:unit.lower().rfind(' utc')]
@@ -861,20 +845,17 @@ def __init__(self, unit, calendar=None):
             unit = _NO_UNIT_STRING
         else:
             category = _CATEGORY_UDUNIT
-            if six.PY2 and not isinstance(unit, six.text_type):
-                str_unit = unit.encode('utf8')
-            else:
-                str_unit = unit
+            str_unit = unit
             try:
                 ut_unit = _ud.parse(_ud_system, unit.encode('utf8'), encoding)
             except _ud.UdunitsError as exception:
                 value_error = _ud_value_error(
                     exception, u'Failed to parse unit "{}"'.format(str_unit))
-                six.raise_from(value_error, None)
+                raise value_error from None
             if _OP_SINCE in unit.lower():
                 if calendar is None:
                     calendar_ = CALENDAR_GREGORIAN
-                elif isinstance(calendar, six.string_types):
+                elif isinstance(calendar, (str,)):
                     calendar_ = calendar.lower()
                     if calendar_ in CALENDAR_ALIASES:
                         calendar_ = CALENDAR_ALIASES[calendar_]
@@ -1234,10 +1215,7 @@ def format(self, option=None):
             encoding_str = _encoding_lookup[encoding]
             result = _ud.format(self.ut_unit, bitmask)
 
-            if six.PY2 and encoding_str != 'ascii':
-                result = six.text_type(result.decode(encoding_str))
-            else:
-                result = str(result.decode(encoding_str))
+            result = str(result.decode(encoding_str))
             return result
 
     @property
@@ -1338,15 +1316,15 @@ def offset_by_time(self, origin):
 
         """
 
-        if not isinstance(origin, (float, six.integer_types)):
+        if not isinstance(origin, (float, (int,))):
             raise TypeError('a numeric type for the origin argument is'
                             ' required')
         try:
             ut_unit = _ud.offset_by_time(self.ut_unit, origin)
         except _ud.UdunitsError as exception:
             value_error = _ud_value_error(
                 exception, 'Failed to offset {!r}'.format(self))
-            six.raise_from(value_error, None)
+            raise value_error from None
         calendar = None
         return Unit._new_from_existing_ut(_CATEGORY_UDUNIT, ut_unit, calendar)
 
@@ -1416,7 +1394,7 @@ def root(self, root):
                     value_error = _ud_value_error(
                         exception,
                         'Failed to take the root of {!r}'.format(self))
-                    six.raise_from(value_error, None)
+                    raise value_error from None
                 calendar = None
                 result = Unit._new_from_existing_ut(
                     _CATEGORY_UDUNIT, ut_unit, calendar)
@@ -1457,7 +1435,7 @@ def log(self, base):
                     exception,
                     'Failed to calculate logorithmic base '
                     'of {!r}'.format(self))
-                six.raise_from(value_err, None)
+                raise value_err from None
             calendar = None
             result = Unit._new_from_existing_ut(
                 _CATEGORY_UDUNIT, ut_unit, calendar)
@@ -1480,12 +1458,6 @@ def __str__(self):
         """
         return self.origin or self.symbol
 
-    if six.PY2:
-        __unicode__ = __str__
-
-        def __str__(self):
-            return unicode(self).encode('utf8')  # noqa: F821
-
     def __repr__(self):
         """
         Returns a string representation of the unit object.
@@ -1555,7 +1527,7 @@ def _op_common(self, other, op_func):
                 value_err = _ud_value_error(
                     exception,
                     'Failed to {} {!r} by {!r}'.format(op_label, self, other))
-                six.raise_from(value_err, None)
+                raise value_err from None
             calendar = None
             result = Unit._new_from_existing_ut(
                 _CATEGORY_UDUNIT, ut_unit, calendar)
@@ -1707,7 +1679,7 @@ def __pow__(self, power):
                     value_err = _ud_value_error(
                         exception,
                         'Failed to raise the power of {!r}'.format(self))
-                    six.raise_from(value_err, None)
+                    raise value_err from None
                 result = Unit._new_from_existing_ut(_CATEGORY_UDUNIT, ut_unit)
         return result
 
@@ -1854,7 +1826,7 @@ def convert(self, value, other, ctype=FLOAT64, inplace=False):
                     value_err = _ud_value_error(
                         exception,
                         'Failed to convert {!r} to {!r}'.format(self, other))
-                    six.raise_from(value_err, None)
+                    raise value_err from None
                 if isinstance(result, np.ndarray):
                     # Can only handle array of np.float32 or np.float64 so
                     # cast array of ints to array of floats of requested

cf_units/config.py

@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2010 - 2018, Met Office
+# (C) British Crown Copyright 2010 - 2020, Met Office
 #
 # This file is part of cf-units.
 #
@@ -16,13 +16,7 @@
 # along with cf-units.  If not, see <http://www.gnu.org/licenses/>.
 
 
-from __future__ import (absolute_import, division, print_function)
-from six.moves import (filter, input, map, range, zip)  # noqa
-
-try:
-    import ConfigParser as configparser
-except ImportError:
-    import configparser
+import configparser
 
 import os.path
 import sys

cf_units/tests/__init__.py

@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2010 - 2018, Met Office
+# (C) British Crown Copyright 2010 - 2020, Met Office
 #
 # This file is part of cf-units.
 #
@@ -14,6 +14,3 @@
 #
 # You should have received a copy of the GNU Lesser General Public License
 # along with cf-units.  If not, see <http://www.gnu.org/licenses/>.
-
-from __future__ import (absolute_import, division, print_function)
-from six.moves import (filter, input, map, range, zip)  # noqa

cf_units/tests/integration/test__num2date_to_nearest_second.py

@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2016 - 2018, Met Office
+# (C) British Crown Copyright 2016 - 2020, Met Office
 #
 # This file is part of cf-units.
 #
@@ -16,9 +16,6 @@
 # along with cf-units.  If not, see <http://www.gnu.org/licenses/>.
 """Test function :func:`cf_units._num2date_to_nearest_second`."""
 
-from __future__ import (absolute_import, division, print_function)
-from six.moves import (filter, input, map, range, zip)  # noqa
-
 import unittest
 import datetime
 

cf_units/tests/integration/test_date2num.py

@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2016 - 2019, Met Office
+# (C) British Crown Copyright 2016 - 2020, Met Office
 #
 # This file is part of cf-units.
 #
@@ -16,14 +16,10 @@
 # along with cf-units.  If not, see <http://www.gnu.org/licenses/>.
 """Test function :func:`cf_units.date2num`."""
 
-from __future__ import (absolute_import, division, print_function)
-from six.moves import (filter, input, map, range, zip)  # noqa
-
 import unittest
 import datetime
 
 import numpy as np
-import six
 
 from cf_units import date2num
 
@@ -74,7 +70,7 @@ def test_long_time_interval(self):
         unit = 'years since 1970-01-01'
         date = datetime.datetime(1970, 1, 1, 0, 0, 5)
         exp_emsg = 'interval of "months", "years" .* got "years".'
-        with six.assertRaisesRegex(self, ValueError, exp_emsg):
+        with self.assertRaisesRegex(ValueError, exp_emsg):
             date2num(date, unit, self.calendar)
 
 

cf_units/tests/test_coding_standards.py

@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2013 - 2019, Met Office
+# (C) British Crown Copyright 2013 - 2020, Met Office
 #
 # This file is part of cf-units.
 #
@@ -15,9 +15,6 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with cf-units.  If not, see <http://www.gnu.org/licenses/>.
 
-from __future__ import (absolute_import, division, print_function)
-from six.moves import (filter, input, map, range, zip)  # noqa
-
 from datetime import datetime
 from fnmatch import fnmatch
 from glob import glob
@@ -190,56 +187,5 @@ def test_license_headers(self):
                 'There were license header failures. See stdout.')
 
 
-class TestFutureImports(unittest.TestCase):
-    excluded = ('*/_version.py')
-
-    future_imports_pattern = re.compile(
-        r"^from __future__ import \(absolute_import,\s*division,\s*"
-        r"print_function(,\s*unicode_literals)?\)$",
-        flags=re.MULTILINE)
-
-    six_import_pattern = re.compile(
-        r"^from six.moves import \(filter, input, map, range, zip\)  # noqa$",
-        flags=re.MULTILINE)
-
-    def test_future_imports(self):
-        # Tests that every single Python file includes the appropriate
-        # __future__ import to enforce consistent behaviour.
-        check_paths = [os.path.dirname(cf_units.__file__)]
-        if DOCS_DIRS:
-            check_paths.extend(DOCS_DIRS)
-
-        failed = False
-        for dirpath, _, files in chain.from_iterable(os.walk(path)
-                                                     for path in check_paths):
-            for fname in files:
-                full_fname = os.path.join(dirpath, fname)
-                if not full_fname.endswith('.py'):
-                    continue
-                if not os.path.isfile(full_fname):
-                    continue
-                if any(fnmatch(full_fname, pat) for pat in self.excluded):
-                    continue
-
-                with open(full_fname, "r") as fh:
-                    content = fh.read()
-
-                    if re.search(self.future_imports_pattern, content) is None:
-                        print('The file {} has no valid __future__ imports '
-                              'and has not been excluded from the imports '
-                              'test.'.format(full_fname))
-                        failed = True
-
-                    if re.search(self.six_import_pattern, content) is None:
-                        print('The file {} has no valid six import '
-                              'and has not been excluded from the imports '
-                              'test.'.format(full_fname))
-                        failed = True
-
-        if failed:
-            raise AssertionError(
-                'There were __future__ import check failures. See stdout.')
-
-
 if __name__ == '__main__':
     unittest.main()