Merge pull request #125 from dupondje/ignore_invalid_time

Fix parsing with invalid timestamps

dsmr_parser/value_types.py

@@ -4,14 +4,23 @@ import pytz
 
 
 def timestamp(value):
-    naive_datetime = datetime.datetime.strptime(value[:-1], '%y%m%d%H%M%S')
+    try:
+        naive_datetime = datetime.datetime.strptime(value[:-1], '%y%m%d%H%M%S')
+    except ValueError:
+        return None
 
-    # TODO comment on this exception
+    # Timestamp has the following format:
+    # YYMMDDhhmmssX
+    # ASCII presentation of Time stamp with
+    # Year, Month, Day, Hour, Minute, Second,
+    # and an indication whether DST is active
+    # (X=S) or DST is not active (X=W)
     if len(value) == 13:
         is_dst = value[12] == 'S'  # assume format 160322150000W
     else:
         is_dst = False
 
+    # TODO : Use system timezone
     local_tz = pytz.timezone('Europe/Amsterdam')
     localized_datetime = local_tz.localize(naive_datetime, is_dst=is_dst)
 

test/test_parse_v5.py

@@ -244,3 +244,21 @@ class TelegramParserV5Test(unittest.TestCase):
         corrupted_telegram = TELEGRAM_V5.replace('!6EEE\r\n', '')
         with self.assertRaises(ParseError):
             TelegramParser.validate_checksum(corrupted_telegram)
+
+    def test_gas_timestamp_invalid(self):
+        # Issue 120
+        # Sometimes a MBUS device (For ex a Gas Meter) returns an invalid timestamp
+        # Instead of failing, we should just ignore the timestamp
+        invalid_date_telegram = TELEGRAM_V5.replace(
+            '0-1:24.2.1(170102161005W)(00000.107*m3)\r\n',
+            '0-1:24.2.1(632525252525S)(00000.000)\r\n'
+        )
+        invalid_date_telegram = invalid_date_telegram.replace('!6EEE\r\n', '!90C2\r\n')
+        parser = TelegramParser(telegram_specifications.V5)
+        result = parser.parse(invalid_date_telegram)
+
+        # HOURLY_GAS_METER_READING (0-1:24.2.1)
+        assert isinstance(result[obis.HOURLY_GAS_METER_READING], MBusObject)
+        assert result[obis.HOURLY_GAS_METER_READING].unit is None
+        assert isinstance(result[obis.HOURLY_GAS_METER_READING].value, Decimal)
+        assert result[obis.HOURLY_GAS_METER_READING].value == Decimal('0.000')