Refactor time zone handling

Author: stephanritscher

src/rctclient/utils.py

@@ -3,7 +3,6 @@
 # Copyright 2020-2021, Stefan Valouch (svalouch)
 # SPDX-License-Identifier: GPL-3.0-only
 
-import pytz
 import struct
 from datetime import datetime
 from typing import overload, Dict, Tuple, Union
@@ -17,8 +16,6 @@
 
 from .types import DataType, EventEntry
 
-timezone = pytz.timezone('Europe/Berlin')
-
 # pylint: disable=invalid-name
 def CRC16(data: Union[bytes, bytearray]) -> int:
     '''
@@ -189,12 +186,12 @@ def _decode_timeseries(data: bytes) -> Tuple[datetime, Dict[datetime, int]]:
     '''
     Helper function to decode the timeseries type.
     '''
-    timestamp = timezone.localize(datetime.utcfromtimestamp(struct.unpack('>I', data[0:4])[0]))
+    timestamp = datetime.utcfromtimestamp(struct.unpack('>I', data[0:4])[0])
     tsval: Dict[datetime, int] = dict()
     assert len(data) % 4 == 0, 'Data should be divisible by 4'
     assert int(len(data) / 4 % 2) == 1, 'Data should be an even number of 4-byte pairs plus the starting timestamp'
     for pair in range(0, int(len(data) / 4 - 1), 2):
-        pair_ts = timezone.localize(datetime.utcfromtimestamp(struct.unpack('>I', data[4 + pair * 4:4 + pair * 4 + 4])[0]))
+        pair_ts = datetime.utcfromtimestamp(struct.unpack('>I', data[4 + pair * 4:4 + pair * 4 + 4])[0])
         pair_val = struct.unpack('>f', data[4 + pair * 4 + 4:4 + pair * 4 + 4 + 4])[0]
         tsval[pair_ts] = pair_val
     return timestamp, tsval
@@ -204,15 +201,15 @@ def _decode_event_table(data: bytes) -> Tuple[datetime, Dict[datetime, EventEntr
     '''
     Helper function to decode the event table type.
     '''
-    timestamp = timezone.localize(datetime.utcfromtimestamp(struct.unpack('>I', data[0:4])[0]))
+    timestamp = datetime.utcfromtimestamp(struct.unpack('>I', data[0:4])[0])
     tabval: Dict[datetime, EventEntry] = dict()
     assert len(data) % 4 == 0
     assert (len(data) - 4) % 20 == 0
     for pair in range(0, int(len(data) / 4 - 1), 5):
         # this is most likely a single byte of information, but this is not sure yet
         # entry_type = bytes([struct.unpack('>I', data[4 + pair * 4:4 + pair * 4 + 4])[0]]).decode('ascii')
         entry_type = struct.unpack('>I', data[4 + pair * 4:4 + pair * 4 + 4])[0]
-        timestamp = timezone.localize(datetime.utcfromtimestamp(struct.unpack('>I', data[4 + pair * 4 + 4:4 + pair * 4 + 8])[0]))
+        timestamp = datetime.utcfromtimestamp(struct.unpack('>I', data[4 + pair * 4 + 4:4 + pair * 4 + 8])[0])
         element2 = struct.unpack('>I', data[4 + pair * 4 + 8:4 + pair * 4 + 12])[0]
         element3 = struct.unpack('>I', data[4 + pair * 4 + 12:4 + pair * 4 + 16])[0]
         element4 = struct.unpack('>I', data[4 + pair * 4 + 16:4 + pair * 4 + 20])[0]
@@ -227,8 +224,8 @@ def _decode_event_table(data: bytes) -> Tuple[datetime, Dict[datetime, EventEntr
         #                                    value_old=value_old, value_new=value_new)
         # the rest is assumed to be range-based events
         # else:
-        #     timestamp_end = timezone.localize(datetime.utcfromtimestamp(
-        #         struct.unpack('>I', data[4 + pair * 4 + 12:4 + pair * 4 + 16])[0]))
+        #     timestamp_end = datetime.utcfromtimestamp(
+        #         struct.unpack('>I', data[4 + pair * 4 + 12:4 + pair * 4 + 16])[0])
         #     object_id = struct.unpack('>I', data[4 + pair * 4 + 16:4 + pair * 4 + 20])[0]
         #     tabval[timestamp] = EventEntry(timestamp=timestamp, object_id=object_id, entry_type=entry_type,
         #                                    timestamp_end=timestamp_end)

tools/timeseries2csv.py

@@ -209,6 +209,7 @@ def timeseries2csv(host: str, port: int, output: Optional[str], header_format: b
 
         while highest_ts > ts_start and not iter_end:
             cprint(f'\ttimestamp: {highest_ts}')
+            # rct power device seems to treat local time at GMT when converting from/to timestamps
             sock.send(make_frame(command=Command.WRITE, id=oid.object_id,
                                  payload=encode_value(DataType.INT32, int(highest_ts.replace(tzinfo=gmt).timestamp()))))
 
@@ -256,6 +257,9 @@ def timeseries2csv(host: str, port: int, output: Optional[str], header_format: b
             # work with the data
             for t_ts, t_val in table.items():
 
+                # rct power device seems to treat local time at GMT when converting from/to timestamps
+                t_ts = timezone.localize(t_ts)
+
                 # set the "highest" point in time to know what to request next when the day is not complete
                 if t_ts < highest_ts:
                     highest_ts = t_ts