Merge pull request #13 from Meisterschueler/reference_datetime

Split reference_datetime to reference_date and reference_time

CHANGELOG.md

@@ -4,6 +4,8 @@
 - Added aprs destination callsign as `dstcall` to aprs beacon keys (#9)
 - Changed aprs parser to allow other destination calls than `APRS`
 - Fixed parsing of APRS precision and datum option (#7)
+- Added optional `reference_time` argument to `parse_aprs` function and disabled
+  magic date correction if this argument is missing
 
 ## 0.4.0 - 2016-03-29
 - aprs client: Added the possibility of a timed callback

README.md

@@ -19,10 +19,10 @@ Parse APRS/OGN packet.
 
 ```
 from ogn.parser import parse_aprs, parse_ogn_beacon
-from datetime import datetime
+from datetime import date, time
 
 beacon = parse_aprs("FLRDDDEAD>APRS,qAS,EDER:/114500h5029.86N/00956.98E'342/049/A=005524 id0ADDDEAD -454fpm -1.1rot 8.8dB 0e +51.2kHz gps4x5",
-                    reference_date=datetime(2016,1,1,11,46))
+                    reference_date=date(2016,1,1), reference_time=time(11,46))
 beacon.update(parse_ogn_beacon(beacon['comment']))
 ```
 

ogn/parser/parse.py

@@ -6,16 +6,18 @@ from ogn.parser.pattern import PATTERN_APRS, PATTERN_RECEIVER_BEACON, PATTERN_AI
 from ogn.parser.exceptions import AprsParseError, OgnParseError
 
 
-def parse_aprs(message, reference_date=None):
+def parse_aprs(message, reference_date=None, reference_time=None):
     if reference_date is None:
-        reference_date = datetime.utcnow()
+        now = datetime.utcnow()
+        reference_date = now.date()
+        reference_time = now.time()
 
     match = re.search(PATTERN_APRS, message)
     if match:
         return {'name': match.group('callsign'),
                 'receiver_name': match.group('receiver'),
                 'dstcall': match.group('dstcall'),
-                'timestamp': createTimestamp(match.group('time'), reference_date),
+                'timestamp': createTimestamp(match.group('time'), reference_date, reference_time),
                 'latitude': parseAngle('0' + match.group('latitude') + (match.group('latitude_enhancement') or '0')) *
                 (-1 if match.group('latitude_sign') == 'S' else 1),
                 'symboltable': match.group('symbol_table'),

ogn/parser/utils.py

@@ -16,12 +16,16 @@ def parseAngle(dddmmhht):
     return float(dddmmhht[:3]) + float(dddmmhht[3:]) / 60
 
 
-def createTimestamp(hhmmss, reference):
+def createTimestamp(hhmmss, reference_date, reference_time=None):
     packet_time = datetime.strptime(hhmmss, '%H%M%S').time()
-    timestamp = datetime.combine(reference, packet_time)
+    if reference_time is None:
-    delta = timestamp - reference
+        return datetime.combine(reference_date, packet_time)
+    else:
+        reference_datetime = datetime.combine(reference_date, reference_time)
+        timestamp = datetime.combine(reference_date, packet_time)
+        delta = timestamp - reference_datetime
 
-    # This function reconstructs the packet date from the timestamp and a reference time.
+        # This function reconstructs the packet date from the timestamp and a reference_datetime time.
         # delta vs. packet date:
         # -24h                      -12h                   0                       +12h                   +24h
         #  |-------------------------|---------------------|------------------------|----------------------|
@@ -32,9 +36,9 @@ def createTimestamp(hhmmss, reference):
             return timestamp
         elif delta < timedelta(hours=-23, minutes=-30):
             # Packet from next day, less than 30min from the future
-        return datetime.combine(reference + timedelta(hours=+12), packet_time)
+            return datetime.combine(reference_datetime + timedelta(hours=+12), packet_time)
         elif timedelta(hours=12) < delta:
             # Packet from previous day, less than 12h from the past
-        return datetime.combine(reference + timedelta(hours=-12), packet_time)
+            return datetime.combine(reference_datetime + timedelta(hours=-12), packet_time)
         else:
-        raise AmbigousTimeError(reference, packet_time)
+            raise AmbigousTimeError(reference_datetime, packet_time)

tests/parser/test_utils.py

@@ -1,5 +1,5 @@
 import unittest
-from datetime import datetime
+from datetime import date, time, datetime
 
 from ogn.parser.utils import parseAngle, createTimestamp
 from ogn.parser.exceptions import AmbigousTimeError
@@ -11,21 +11,22 @@ class TestStringMethods(unittest.TestCase):
 
     def test_createTimestamp(self):
         test_data = [
-            ('000001', datetime(2015, 1, 10, 0, 0, 1), datetime(2015, 1, 10, 0, 0, 1)),      # packet from current day (on the tick)
+            ('000001', date(2015, 1, 10), time(0, 0, 1), datetime(2015, 1, 10, 0, 0, 1)),      # packet from current day (on the tick)
-            ('235959', datetime(2015, 1, 10, 0, 0, 1), datetime(2015, 1, 9, 23, 59, 59)),    # packet from previous day (2 seconds old)
+            ('235959', date(2015, 1, 10), time(0, 0, 1), datetime(2015, 1, 9, 23, 59, 59)),    # packet from previous day (2 seconds old)
-            ('110000', datetime(2015, 1, 10, 0, 0, 1), None),                                # packet 11 hours from future or 13 hours old
+            ('110000', date(2015, 1, 10), time(0, 0, 1), None),                                # packet 11 hours from future or 13 hours old
-            ('123500', datetime(2015, 1, 10, 23, 50, 0), datetime(2015, 1, 10, 12, 35, 0)),  # packet from current day (11 hours old)
+            ('123500', date(2015, 1, 10), time(23, 50, 0), datetime(2015, 1, 10, 12, 35, 0)),   # packet from current day (11 hours old)
-            ('000001', datetime(2015, 1, 10, 23, 50, 0), datetime(2015, 1, 11, 0, 0, 1))     # packet from next day (11 minutes from future)
+            ('000001', date(2015, 1, 10), time(23, 50, 0), datetime(2015, 1, 11, 0, 0, 1)),     # packet from next day (11 minutes from future)
+            ('000001', date(2015, 1, 10), None, datetime(2015, 1, 10, 0, 0, 1)),                # first packet of a specific day
+            ('235959', date(2015, 1, 10), None, datetime(2015, 1, 10, 23, 59, 59)),             # last packet of a specific day
         ]
 
         for test in test_data:
-            if test[2]:
+            if test[3]:
-                timestamp = createTimestamp(test[0], reference=test[1])
+                timestamp = createTimestamp(test[0], reference_date=test[1], reference_time=test[2])
-                self.assertEqual(timestamp, test[2])
+                self.assertEqual(timestamp, test[3])
             else:
                 with self.assertRaises(AmbigousTimeError):
-                    createTimestamp(test[0], reference=test[1])
+                    createTimestamp(test[0], reference_date=test[1], reference_time=test[2])
-
 
 if __name__ == '__main__':
     unittest.main()