Added pylint config, code improvements suggested by pylint

6 files changed, 87 insertions, 59 deletions

diff --git a/lab_control/__init__.py b/lab_control/__init__.py
index b8c59c6..e69de29 100644
--- a/lab_control/__init__.py
+++ b/lab_control/__init__.py
@@ -1,3 +0,0 @@
-#from os.path import dirname, abspath
-
-#ROOT_DIR = dirname(abspath(__file__))
diff --git a/lab_control/function_generator.py b/lab_control/function_generator.py
index be522d9..a403784 100644
--- a/lab_control/function_generator.py
+++ b/lab_control/function_generator.py
@@ -1,23 +1,24 @@
-class FunctionGenerator:
-    SINE       = 0
-    SQUARE     = 1
-    TRIANGULAR = 3
+""" Interface definition for function generator devices. """
 
+class FunctionGenerator:
+    """
+    This interface specifies the common API for all
+    supported function generator devices.
+    """
     def __init__(self):
-        raise Exception("This class should not be instantiated directly, please extend it instead")
+        pass
 
     def setOn(self, channel: int) -> None:
-        pass
+        """ Enable channel. """
 
     def setOff(self, channel: int) -> None:
-        pass
+        """ Disable channel. """
 
     def setFrequency(self, channel: int, frequency: float) -> None:
-        pass
+        """ Set channel output frequency. """
 
     def setAmplitude(self, channel: int, amplitude: float) -> None:
-        pass
+        """ Set channel output amplitude. """
 
     def setFunction(self, channel: int, function: int) -> None:
-        pass
-
+        """ Set channel output waveform. """
diff --git a/lab_control/jds6600.py b/lab_control/jds6600.py
index 006a041..5ada6cf 100644
--- a/lab_control/jds6600.py
+++ b/lab_control/jds6600.py
@@ -1,25 +1,44 @@
+"""
+Implements partial support for Joy-IT JDS6600 function generator.
+"""
+
 import serial
-import re
 
 from lab_control.function_generator import FunctionGenerator
 
+def _checkChannel(channel: int):
+    assert channel in JDS6600.AVAILABLE_CHANNELS, f"JDS6600: Invalid channel {channel}"
+
+def _checkArg(arg: float, lowerBound: float, upperBound: float):
+    valid = arg is not None
+    if valid:
+        valid &= arg >= lowerBound
+        valid &= arg <= upperBound
+    assert valid, f"JDS6600: Invalid argument {arg}"
+
 class JDS6600(FunctionGenerator):
+    """
+    Instances of this class bind to the JDS6600 serial port
+    and offer an API to control the device.
+    """
     AVAILABLE_CHANNELS = [1, 2]
+    SINE       = 0
+    SQUARE     = 1
+    TRIANGULAR = 3
 
     def __init__(self, portName):
+        super().__init__()
         self._port = serial.Serial(portName)
         self._port.baudrate = 115200
         self._port.bytesize = serial.EIGHTBITS
         self._port.stopbits = serial.STOPBITS_ONE
         self._port.parity = serial.PARITY_NONE
 
-    def _sendRequest(self, opcode: str, args: str="") -> str:
-        request = f":{opcode}={args}.\r\n"
-        self._port.write(request.encode())
-        responseRaw = self._port.readline()
-        return responseRaw.decode().strip()
-
     def closePort(self) -> None:
+        """
+        Close the serial port. Instances of this class
+        are no longer usable after this is called.
+        """
         self._port.close()
 
     def _queryOnOff(self) -> list[str, str]:
@@ -27,39 +46,45 @@ class JDS6600(FunctionGenerator):
         response = self._sendRequest("r20")
         return [response[5], response[7]]
 
+    def _sendRequest(self, opcode: str, args: str="") -> str:
+        request = f":{opcode}={args}.\r\n"
+        self._port.write(request.encode())
+        responseRaw = self._port.readline()
+        return responseRaw.decode().strip()
+
     def setOn(self, channel: int) -> None:
-        assert channel in JDS6600.AVAILABLE_CHANNELS, f"JDS6600: Invalid channel {channel}"
+        _checkChannel(channel)
 
         state = self._queryOnOff()
         state[channel - 1] = "1"
-        response = self._sendRequest("w20", f"{state[0]},{state[1]}")
+        self._sendRequest("w20", f"{state[0]},{state[1]}")
 
     def setOff(self, channel: int) -> None:
-        assert channel in JDS6600.AVAILABLE_CHANNELS, f"JDS6600: Invalid channel {channel}"
+        _checkChannel(channel)
 
         state = self._queryOnOff()
         state[channel - 1] = "0"
-        response = self._sendRequest("w20", f"{state[0]},{state[1]}")
+        self._sendRequest("w20", f"{state[0]},{state[1]}")
 
     def setFrequency(self, channel: int, frequency: float) -> None:
-        assert channel in JDS6600.AVAILABLE_CHANNELS, f"JDS6600: Invalid channel {channel}"
-        assert frequency is not None and frequency >= 0.0 and frequency <= 60e6, f"JDS6600: Invalid frequency {frequency}"
+        _checkChannel(channel)
+        _checkArg(frequency, 0.0, 60e6)
 
         opcode = f"w{23 + channel - 1}"
         arg = int(frequency * 100.0)
-        response = self._sendRequest(opcode, str(arg))
+        self._sendRequest(opcode, str(arg))
 
     def setAmplitude(self, channel: int, amplitude: float) -> None:
-        assert channel in JDS6600.AVAILABLE_CHANNELS, f"JDS6600: Invalid channel {channel}"
-        assert amplitude is not None and amplitude >= 0.0 and amplitude <= 20.0, f"JDS6600: Invalid amplitude {amplitude}"
+        _checkChannel(channel)
+        _checkArg(amplitude, 0.0, 20.0)
 
         opcode = f"w{25 + channel - 1}"
         arg = int(amplitude * 1000.0)
-        response = self._sendRequest(opcode, str(arg))
+        self._sendRequest(opcode, str(arg))
 
     def setFunction(self, channel: int, function: int) -> None:
-        assert channel in JDS6600.AVAILABLE_CHANNELS, f"JDS6600: Invalid channel {channel}"
-        assert function is not None and function >= 0 and function <= 16, f"JDS6600: Invalid function code {function}"
+        _checkChannel(channel)
+        _checkArg(function, 0, 16)
 
         opcode = f"w{21 + channel - 1}"
-        response = self._sendRequest(opcode, str(function))
+        self._sendRequest(opcode, str(function))
diff --git a/lab_control/oscilloscope.py b/lab_control/oscilloscope.py
index 9f2d02c..e4b5a89 100644
--- a/lab_control/oscilloscope.py
+++ b/lab_control/oscilloscope.py
@@ -1,17 +1,21 @@
+""" Interface definition for oscilloscope devices. """
+
 class Oscilloscope:
+    """
+    This interface specifies the common API for all
+    supported oscilloscope devices.
+    """
     def __init__(self):
-        raise Exception("This class should not be instantiated directly, please extend it instead")
+        pass
 
     def measureAmplitude(self, channel: int) -> float:
-        pass
+        """ Return amplitude measurement on specific channel. """
 
     def measurePeakToPeak(self, channel: int) -> float:
-        pass
+        """ Return peak-to-peak measurement on specific channel. """
 
     def measureRMS(self, channel: int) -> float:
-        pass
+        """ Return RMS measurement on specific channel. """
 
     def measureFrequency(self, channel: int) -> float:
-        pass
-
-
+        """ Return frequency measurement on specific channel. """
diff --git a/lab_control/sds1000xe.py b/lab_control/sds1000xe.py
index 859b1bf..67fc29b 100644
--- a/lab_control/sds1000xe.py
+++ b/lab_control/sds1000xe.py
@@ -1,31 +1,44 @@
+"""
+Implements partial support for Siglent SDS1000X-E series oscilloscopes.
+"""
+
 import socket
 import re
 from lab_control.oscilloscope import Oscilloscope
 
+def _checkChannel(channel):
+    assert channel in SDS1000XE.AVAILABLE_CHANNELS, "SDS1000X-E: Invalid channel {channel}"
+
 class SDS1000XE(Oscilloscope):
+    """
+    Instances of this class connect to the SDS1000X-E IP
+    and port and offer an API to control the device.
+    """
     PORT = 5025
     TIMEOUT = 1.0
     AVAILABLE_CHANNELS = range(1, 5)
 
     def __init__(self, address):
+        super().__init__()
         self._socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         self._socket.connect((address, SDS1000XE.PORT))
         self._socket.settimeout(SDS1000XE.TIMEOUT)
 
-    def _measure(self, channel: int, code: str) -> float:
-        assert channel in SDS1000XE.AVAILABLE_CHANNELS, "SDS1000X-E: Invalid channel {channel}"
 
+    def _measure(self, channel: int, code: str) -> float:
+        _checkChannel(channel)
+        pattern = r"C(?P<responseChannel>\d):PAVA .+,(?P<rawMeasurement>[\d.E+-]+)\w+"
         query = f"C{channel}:PAVA? {code}\r\n"
         self._socket.sendall(query.encode())
 
         try:
             # TODO add code to regex
             response = self._socket.recv(4096).decode()
-            m = re.search(r"C(?P<responseChannel>\d):PAVA .+,(?P<rawMeasurement>[\d.E+-]+)\w+", response)
-            measurement = float(m.group("rawMeasurement"))
-        except TimeoutError as e:
+            matches = re.search(pattern, response)
+            measurement = float(matches.group("rawMeasurement"))
+        except TimeoutError:
             measurement = None
-        
+
         return measurement
 
     def measureAmplitude(self, channel: int) -> float:
@@ -39,4 +52,3 @@ class SDS1000XE(Oscilloscope):
 
     def measureFrequency(self, channel: int) -> float:
         return self._measure(channel, "FREQ")
-
diff --git a/lab_control/test/interfaces_test.py b/lab_control/test/interfaces_test.py
deleted file mode 100644
index bf9006b..0000000
--- a/lab_control/test/interfaces_test.py
+++ /dev/null
@@ -1,11 +0,0 @@
-import pytest
-from lab_control.oscilloscope import Oscilloscope
-from lab_control.function_generator import FunctionGenerator
-
-def test_oscilloscopeInterface():
-    with pytest.raises(Exception):
-        uut = Oscilloscope()
-
-def test_functionGeneratorInterface():
-    with pytest.raises(Exception):
-        uut = FunctionGenerator()