Changeset 8185

Timestamp:

16 Apr 2012, 23:17:35 (13 years ago)

Author:

uli

Message:

Add datetime/timezone helpers urgently needed.

Location:

main/waeup.kofa/trunk/src/waeup/kofa/utils

Files:

• helpers.py (modified) (2 diffs)
• tests/test_helpers.py (modified) (3 diffs)

main/waeup.kofa/trunk/src/waeup/kofa/utils/helpers.py

@@ -18 +18 @@
 """General helper functions for Kofa.
 """
+import datetime
 import os
+import pytz
 import re
 import shutil
@@ -550 +552 @@
             result.append((title, code))
     return tuple(result)
+
+def now(tz=None):
+    """Get current datetime in timezone of `tz`.
+
+    If `tz`, a `tzinfo` instance, is None, UTC time is returned.
+
+    `tz` should be a timezone as defined in pytz.
+    """
+    return to_timezone(datetime.datetime.utcnow(), tz=tz)
+
+def to_timezone(dt, tz=None):
+    """Shift datetime into timezone `tz`.
+
+    If datetime `dt` contains no `tzinfo` (i.e. it is 'naive'), it is
+    assumed to be UTC.
+
+    If no `tz` is given, shift to UTC is performed.
+    """
+    if tz is None:
+        tz = pytz.utc
+    if dt.tzinfo is None:
+        dt = pytz.utc.localize(dt)
+    return tz.normalize(dt.tzinfo.normalize(dt).astimezone(tz))

main/waeup.kofa/trunk/src/waeup/kofa/utils/tests/test_helpers.py

@@ -19 +19 @@
 ##
 
+import datetime
 import os
+import pytz
 import shutil
 import tempfile
@@ -262 +264 @@
         self.assertEqual(sorted(result5), ['baz'])
         return
+
+class DateTimeHelpersTestCase(unittest.TestCase):
+
+    def test_now(self):
+        tz_berlin = pytz.timezone('Europe/Berlin')
+        result1 = helpers.now()
+        result2 = helpers.now(tz_berlin)
+        self.assertEqual(result1.tzinfo, pytz.utc)
+        self.assertFalse(result2.tzinfo == pytz.utc)
+        self.assertFalse(result2.tzinfo is None)
+        return
+
+    def test_to_timezone(self):
+        fmt = '%Y-%m-%d %H:%M:%S %Z%z'
+        tz_berlin = pytz.timezone('Europe/Berlin')
+        tz_lagos = pytz.timezone('Africa/Lagos')
+        dt1 = datetime.datetime(2012, 1, 1, 0, 0)
+        dt2 = datetime.datetime(2012, 1, 1, 0, 0, tzinfo=tz_berlin)
+        dt3 = datetime.datetime(2012, 6, 1, 0, 0, tzinfo=tz_lagos)
+        dt4 = datetime.datetime(2012, 6, 1, 0, 0, tzinfo=tz_berlin)
+        result1 = helpers.to_timezone(dt1)
+        result2 = helpers.to_timezone(dt1, pytz.utc)
+        result3 = helpers.to_timezone(dt2)
+        result4 = helpers.to_timezone(dt2, tz_lagos)
+        result5 = helpers.to_timezone(dt3, tz_berlin)
+        result6 = helpers.to_timezone(dt4, tz_lagos)
+        self.assertEqual(
+            result1.strftime(fmt), '2012-01-01 00:00:00 UTC+0000')
+        self.assertEqual(
+            result2.strftime(fmt), '2012-01-01 00:00:00 UTC+0000')
+        self.assertEqual(
+            result3.strftime(fmt), '2011-12-31 23:00:00 UTC+0000')
+        self.assertEqual(
+            result4.strftime(fmt), '2012-01-01 00:00:00 WAT+0100')
+        self.assertEqual(
+            result5.strftime(fmt), '2012-06-01 01:46:00 CEST+0200')
+        self.assertEqual(
+            result6.strftime(fmt), '2012-06-01 00:00:00 WAT+0100')
+        return
+
 
 def test_suite():
@@ -275 +317 @@
         FileSizeTestCase,
         IfaceNamesTestCase,
+        DateTimeHelpersTestCase,
         ]:
         suite.addTests(