python3 - 2to3 + miscell obvious tweaks

[sfa.git] / sfa / util / sfatime.py

diff --git a/sfa/util/sfatime.py b/sfa/util/sfatime.py
index d14f44b..6793ad5 100644 (file)
--- a/sfa/util/sfatime.py
+++ b/sfa/util/sfatime.py
@@ -20,54 +20,110 @@
 # OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS
 # IN THE WORK.
 #----------------------------------------------------------------------
-from types import StringTypes
-import dateutil.parser
-import datetime
+
+
 import time
+import datetime
+import dateutil.parser
+import calendar
+import re
 
 from sfa.util.sfalogging import logger
+from sfa.util.py23 import StringType
 
 SFATIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
 
+
 def utcparse(input):
     """ Translate a string into a time using dateutil.parser.parse but make sure it's in UTC time and strip
 the timezone, so that it's compatible with normal datetime.datetime objects.
 
 For safety this can also handle inputs that are either timestamps, or datetimes
 """
+
+    def handle_shorthands(input):
+        """recognize string like +5d or +3w or +2m as 
+        2 days, 3 weeks or 2 months from now"""
+        if input.startswith('+'):
+            match = re.match(r"([0-9]+)([dwm])", input[1:])
+            if match:
+                how_many = int(match.group(1))
+                what = match.group(2)
+                if what == 'd':
+                    d = datetime.timedelta(days=how_many)
+                elif what == 'w':
+                    d = datetime.timedelta(weeks=how_many)
+                elif what == 'm':
+                    d = datetime.timedelta(weeks=4 * how_many)
+                return datetime.datetime.utcnow() + d
+
     # prepare the input for the checks below by
     # casting strings ('1327098335') to ints
-    if isinstance(input, StringTypes):
+    if isinstance(input, StringType):
         try:
             input = int(input)
         except ValueError:
-            pass
+            try:
+                new_input = handle_shorthands(input)
+                if new_input is not None:
+                    input = new_input
+            except:
+                import traceback
+                traceback.print_exc()
 
-    if isinstance (input, datetime.datetime):
-        logger.warn ("argument to utcparse already a datetime - doing nothing")
+    # here we go
+    if isinstance(input, datetime.datetime):
+        #logger.info ("argument to utcparse already a datetime - doing nothing")
         return input
-    elif isinstance (input, StringTypes):
+    elif isinstance(input, StringType):
         t = dateutil.parser.parse(input)
         if t.utcoffset() is not None:
             t = t.utcoffset() + t.replace(tzinfo=None)
         return t
-    elif isinstance (input, (int,float,long)):
+    elif isinstance(input, (int, float)):
         return datetime.datetime.fromtimestamp(input)
     else:
-        logger.error("Unexpected type in utcparse [%s]"%type(input))
+        logger.error("Unexpected type in utcparse [%s]" % type(input))
+
+
+def datetime_to_string(dt):
+    return datetime.datetime.strftime(dt, SFATIME_FORMAT)
+
 
-def datetime_to_string(input):
-    return datetime.datetime.strftime(input, SFATIME_FORMAT)
+def datetime_to_utc(dt):
+    return time.gmtime(datetime_to_epoch(dt))
 
-def datetime_to_utc(input):
-    return time.gmtime(datetime_to_epoch(input))
+# see https://docs.python.org/2/library/time.html
+# all timestamps are in UTC so time.mktime() would be *wrong*
 
-def datetime_to_epoch(input):
-    return int(time.mktime(input.timetuple()))
 
-def adjust_datetime(input, days=0, hours=0, minutes=0, seconds=0):
+def datetime_to_epoch(dt):
+    return int(calendar.timegm(dt.timetuple()))
+
+
+def add_datetime(input, days=0, hours=0, minutes=0, seconds=0):
     """
     Adjust the input date by the specified delta (in seconds).
     """
     dt = utcparse(input)
     return dt + datetime.timedelta(days=days, hours=hours, minutes=minutes, seconds=seconds)
+
+if __name__ == '__main__':
+        # checking consistency
+    print(20 * 'X')
+    print(("Should be close to zero: %s" %
+           (datetime_to_epoch(datetime.datetime.utcnow()) - time.time())))
+    print(20 * 'X')
+    for input in [
+            '+2d',
+            '+3w',
+            '+2m',
+            1401282977.575632,
+            1401282977,
+            '1401282977',
+            '2014-05-28',
+            '2014-05-28T15:18',
+            '2014-05-28T15:18:30',
+    ]:
+        print("input=%20s -> parsed %s" %
+              (input, datetime_to_string(utcparse(input))))