address some pylint concerns

pyLSV2/client.py

@@ -1290,7 +1290,6 @@ def read_plc_memory(self, first_element: int, mem_type: lc.MemoryType, number_of
                     )
                     return []
         else:
-
             max_elements_per_transfer = math.floor(255 / mem_byte_count) - 1  # subtract 1 for safety
             num_groups = math.ceil(number_of_elements / max_elements_per_transfer)
             logging.debug(
@@ -1303,7 +1302,6 @@ def read_plc_memory(self, first_element: int, mem_type: lc.MemoryType, number_of
             first_element_in_group = first_element
 
             for i in range(num_groups):
-
                 # determine number of elements for this group
                 if remaining_elements > max_elements_per_transfer:
                     elements_in_group = max_elements_per_transfer
@@ -1660,9 +1658,11 @@ def read_data_path(self, path: str) -> Union[bool, int, float, str, None]:
 
             self._logger.info("successfully read data path: %s and got value '%s'", path, data_value)
             return data_value
-        elif self.last_error.e_code == lc.LSV2StatusCode.T_ER_WRONG_PARA:
+
+        if self.last_error.e_code == lc.LSV2StatusCode.T_ER_WRONG_PARA:
             self._logger.warning("the argument '%s' is not supported by this control", path)
             return None
+
         self._logger.warning("an error occurred while querying data path '%s'. Error code was %d", path, self.last_error.e_code)
         return None
 
@@ -1748,13 +1748,13 @@ def read_scope_signals(self) -> List[ld.ScopeSignal]:
         """
         if not self.versions.is_itnc():
             self._logger.warning("only works for iTNC530")
-            return list()
+            return []
 
         if not self.login(lc.Login.SCOPE):
             self._logger.warning("clould not log in as user for scope function")
-            return list()
+            return []
 
-        channel_list = list()
+        channel_list = []
 
         content = self._llcom.telegram(lc.CMD.R_OC)
         if self._llcom.last_response in lc.RSP.S_OC:
@@ -1788,11 +1788,11 @@ def real_time_readings(self, signal_list: List[ld.ScopeSignal], duration: int, i
         """
         if not self.versions.is_itnc():
             self._logger.warning("only works for iTNC530")
-            return list()
+            return []
 
         if not self.login(lc.Login.SCOPE):
             self._logger.warning("clould not log in as user for scope function")
-            return list()
+            return []
 
         self._logger.debug(
             "start recoding %d readings with interval of %d µs",
@@ -1831,7 +1831,7 @@ def real_time_readings(self, signal_list: List[ld.ScopeSignal], duration: int, i
         payload.extend(struct.pack("!L", interval))
 
         start = time.time()  # start timer
-        recorded_data = list()
+        recorded_data = []
         content = self._send_recive(lc.CMD.R_OD, payload, lc.RSP.S_OD)
 
         if not isinstance(content, (bytearray,)) or len(content) <= 0:
@@ -1851,6 +1851,6 @@ def real_time_readings(self, signal_list: List[ld.ScopeSignal], duration: int, i
                 break
             end = time.time()
             timer = end - start
-            recorded_data = list()
+            recorded_data = []
 
         self._logger.debug("finished reading scope data")

pyLSV2/dat_cls.py

@@ -1158,7 +1158,7 @@ def __init__(self, channel: int, signal: int, offset: int, factor: float, unit:
         self._unit = unit
 
         # self._header = bytearray()
-        self.data = list()
+        self.data = []
 
     @property
     def channel(self) -> int:
@@ -1199,7 +1199,7 @@ class ScopeReading:
     def __init__(self, sequence_number: int):
         self._seqence_nr = sequence_number
         # self._full_data = bytearray()
-        self._signal_data = list()
+        self._signal_data = []
 
     def seqence_nr(self) -> int:
         """sequence number of consecuetive readings"""

pyLSV2/low_level_com.py

@@ -253,7 +253,7 @@ def __init__(self, port: str, speed: int, timeout: float = 15.0):
         self._last_lsv2_response = RSP.NONE
         self._last_error = LSV2Error()
         raise NotImplementedError()
-        import serial
+        # import serial
 
     @property
     def last_response(self) -> RSP:
@@ -287,14 +287,12 @@ def connect(self):
         Establish connection to control
         """
         raise NotImplementedError()
-        pass
 
     def disconnect(self):
         """
         Close connection
         """
         raise NotImplementedError()
-        pass
 
     def telegram(
         self,

pyLSV2/misc.py

@@ -89,18 +89,19 @@ def decode_system_information(data_set: bytearray) -> Union[bool, int]:
 
     if data_type == 1:
         return struct.unpack("!xxx?", data_set[4:])[0]
-    elif data_type == 2:
+
+    if data_type == 2:
         return struct.unpack("!L", data_set[4:])[0]
-    else:
-        raise LSV2DataException("unexpected value for data type of system information")
+
+    raise LSV2DataException("unexpected value for data type of system information")
     # always returns b"\x00\x00\x00\x02\x00\x00\x0b\xb8" for recording 1, 2 and 3
     # -> is independent of channel, axes, interval or samples
     # maybe the last four bytes are the actual interval? 0x00 00 0b b8 = 3000
     # documentation hints
-    if data_set != bytearray(b"\x00\x00\x00\x02\x00\x00\x0b\xb8"):
-        print(" # unexpected return pattern for R_CI!")
-        raise Exception("unknown data for S_CI result")
-    return data_set
+    # if data_set != bytearray(b"\x00\x00\x00\x02\x00\x00\x0b\xb8"):
+    #    print(" # unexpected return pattern for R_CI!")
+    #    raise Exception("unknown data for S_CI result")
+    # return data_set
 
 
 def decode_file_system_info(data_set: bytearray, control_type: ControlType = ControlType.UNKNOWN) -> ld.FileEntry:

tests/test_plc_read.py

@@ -115,7 +115,6 @@ def test_comapare_values(address: str, timeout: float):
     lsv2.connect()
 
     if lsv2.versions.is_itnc():
-
         for mem_address in [0, 1, 2, 4, 8, 12, 68, 69, 151, 300, 368]:
             v1 = lsv2.read_plc_memory(mem_address, pyLSV2.MemoryType.DWORD, 1)[0]
             v2 = lsv2.read_data_path("/PLC/memory/D/%d" % (mem_address * 4))