15 files changed, 50 insertions, 74 deletions

diff --git a/glucometerutils/common.py b/glucometerutils/common.py
index 6576ebd..50f04e7 100644
--- a/glucometerutils/common.py
+++ b/glucometerutils/common.py
@@ -154,23 +154,16 @@ class MeterInfo:
             version_information_string = "\n    ".join(self.version_info).strip()
 
         base_output = textwrap.dedent(
-            """\
-            {model}
-            Serial Number: {serial_number}
+            f"""\
+            {self.model}
+            Serial Number: {self.serial_number}
             Version Information:
                 {version_information_string}
-            Native Unit: {native_unit}
+            Native Unit: {self.native_unit.value}
         """
-        ).format(
-            model=self.model,
-            serial_number=self.serial_number,
-            version_information_string=version_information_string,
-            native_unit=self.native_unit.value,
         )
 
         if self.patient_name != None:
-            base_output += "Patient Name: {patient_name}\n".format(
-                patient_name=self.patient_name
-            )
+            base_output += f"Patient Name: {self.patient_name}\n"
 
         return base_output
diff --git a/glucometerutils/drivers/accuchek_reports.py b/glucometerutils/drivers/accuchek_reports.py
index c4d7527..e6dc2ea 100644
--- a/glucometerutils/drivers/accuchek_reports.py
+++ b/glucometerutils/drivers/accuchek_reports.py
@@ -57,7 +57,7 @@ class Device(driver_base.GlucometerDriver):
         report_files = glob.glob(reports_path)
         if not report_files:
             raise exceptions.ConnectionFailed(
-                'No report file found in path "%s".' % reports_path
+                f'No report file found in path "{reports_path}".'
             )
 
         self.report_file = report_files[0]
@@ -80,7 +80,7 @@ class Device(driver_base.GlucometerDriver):
 
     def get_meter_info(self):
         return common.MeterInfo(
-            "%s glucometer" % self.get_model(),
+            f"{self.get_model()} glucometer",
             serial_number=self.get_serial_number(),
             native_unit=self.get_glucose_unit(),
         )
diff --git a/glucometerutils/drivers/fslibre.py b/glucometerutils/drivers/fslibre.py
index 29e821a..4802673 100644
--- a/glucometerutils/drivers/fslibre.py
+++ b/glucometerutils/drivers/fslibre.py
@@ -162,28 +162,24 @@ def _parse_arresult(record):
         comment_parts.append("Medication")
 
     if parsed_record["food-flag"]:
-        if parsed_record["food-carbs-grams"]:
-            comment_parts.append("Food (%d g)" % parsed_record["food-carbs-grams"])
+        grams = parsed_record["food-carbs-grams"]
+        if grams:
+            comment_parts.append(f"Food ({grams} g)")
         else:
             comment_parts.append("Food")
 
     if parsed_record["long-acting-flag"]:
-        if parsed_record["double-long-acting-insulin"]:
-            comment_parts.append(
-                "Long-acting insulin (%.1f)"
-                % (parsed_record["double-long-acting-insulin"] / 2.0)
-            )
+        insulin = parsed_record["double-long-acting-insulin"] / 2
+        if insulin:
+            comment_parts.append(f"Long-acting insulin ({insulin:.1f})")
         else:
             comment_parts.append("Long-acting insulin")
 
     if parsed_record["rapid-acting-flag"]:
-        # provide default value, as this record does not always exist
-        # (even if rapid-acting-flag is set)
-        if parsed_record.get("double-rapid-acting-insulin", 0):
-            comment_parts.append(
-                "Rapid-acting insulin (%.1f)"
-                % (parsed_record["double-rapid-acting-insulin"] / 2.0)
-            )
+        # This record does not always exist, so calculate it only when present.
+        if "double-rapid-acting-insulin" in parsed_record:
+            rapid_insulin = parsed_record["double-rapid-acting-insulin"] / 2
+            comment_parts.append(f"Rapid-acting insulin ({rapid_insulin:.1f})")
         else:
             comment_parts.append("Rapid-acting insulin")
 
diff --git a/glucometerutils/drivers/fsoptium.py b/glucometerutils/drivers/fsoptium.py
index 5c3971e..77244af 100644
--- a/glucometerutils/drivers/fsoptium.py
+++ b/glucometerutils/drivers/fsoptium.py
@@ -89,7 +89,7 @@ class Device(serial.SerialDevice, driver_base.GlucometerDriver):
     DEFAULT_CABLE_ID = "1a61:3420"
 
     def _send_command(self, command):
-        cmd_bytes = bytes("$%s\r\n" % command, "ascii")
+        cmd_bytes = bytes(f"$%s\r\n" % command, "ascii")
         logging.debug("Sending command: %r", cmd_bytes)
 
         self.serial_.write(cmd_bytes)
diff --git a/glucometerutils/drivers/otultraeasy.py b/glucometerutils/drivers/otultraeasy.py
index 0d1e7a9..ba8067f 100644
--- a/glucometerutils/drivers/otultraeasy.py
+++ b/glucometerutils/drivers/otultraeasy.py
@@ -152,8 +152,7 @@ class Device(serial.SerialDevice, driver_base.GlucometerDriver):
             pkt.link_control.sequence_number != self.expect_receive_
         ):
             raise lifescan.MalformedCommand(
-                "at position 2[0b] expected %02x, received %02x"
-                % (self.expect_receive_, pkt.link_connect.sequence_count)
+                f"at position 2[0b] expected {self.expect_receive_:02x}, received {pkt.link_connect.sequence_count:02x}"
             )
 
         return pkt
diff --git a/glucometerutils/drivers/otverio2015.py b/glucometerutils/drivers/otverio2015.py
index b8429ea..fee84f0 100644
--- a/glucometerutils/drivers/otverio2015.py
+++ b/glucometerutils/drivers/otverio2015.py
@@ -123,7 +123,7 @@ class Device(driver_base.GlucometerDriver):
         vendor = inq.result["t10_vendor_identification"][:32]
         if vendor != b"LifeScan":
             raise exceptions.ConnectionFailed(
-                "Device %s is not a LifeScan glucometer." % self.device_name_
+                f"Device {self.device_name_} is not a LifeScan glucometer."
             )
 
     def disconnect(self):  # pylint: disable=no-self-use
@@ -176,10 +176,11 @@ class Device(driver_base.GlucometerDriver):
         return response.value
 
     def get_meter_info(self):
+        model = self._query_string("model")
         return common.MeterInfo(
-            "OneTouch %s glucometer" % self._query_string("model"),
+            f"OneTouch {model} glucometer",
             serial_number=self.get_serial_number(),
-            version_info=("Software version: " + self.get_version(),),
+            version_info=(f"Software version: {self.get_version()}",),
             native_unit=self.get_glucose_unit(),
         )
 
diff --git a/glucometerutils/drivers/sdcodefree.py b/glucometerutils/drivers/sdcodefree.py
index 47dd9ca..08a3afc 100644
--- a/glucometerutils/drivers/sdcodefree.py
+++ b/glucometerutils/drivers/sdcodefree.py
@@ -105,14 +105,14 @@ class Device(serial.SerialDevice, driver_base.GlucometerDriver):
                 continue
             if challenge != b"\x53":
                 raise exceptions.ConnectionFailed(
-                    message="Unexpected starting bytes %r" % challenge
+                    message=f"Unexpected starting bytes {challenge!r}"
                 )
 
         challenge += self.serial_.read(6)
 
         if challenge != _CHALLENGE_PACKET_FULL:
             raise exceptions.ConnectionFailed(
-                message="Unexpected challenge %r" % challenge
+                message=f"Unexpected challenge {challenge!r}"
             )
 
         logging.debug("challenge packet received: %s", binascii.hexlify(challenge))
diff --git a/glucometerutils/drivers/td4277.py b/glucometerutils/drivers/td4277.py
index 0385299..106166e 100644
--- a/glucometerutils/drivers/td4277.py
+++ b/glucometerutils/drivers/td4277.py
@@ -157,7 +157,7 @@ class Device(serial.SerialDevice, driver_base.GlucometerDriver):
         )
         if response_command not in _VALID_CONNECT_RESPONSE:
             raise exceptions.ConnectionFailed(
-                "Invalid response received: %2x %r" % (response_command, message)
+                f"Invalid response received: {response_command:02x} {message!r}"
             )
 
         _, model_message = self._send_command(_GET_MODEL)
@@ -165,7 +165,7 @@ class Device(serial.SerialDevice, driver_base.GlucometerDriver):
             _MODEL_STRUCT.parse(model_message)
         except construct.ConstructError:
             raise exceptions.ConnectionFailed(
-                "Invalid model identified: %r" % model_message
+                f"Invalid model identified: {model_message!r}"
             )
 
     def disconnect(self):
diff --git a/glucometerutils/exceptions.py b/glucometerutils/exceptions.py
index 52e4d22..1f72308 100644
--- a/glucometerutils/exceptions.py
+++ b/glucometerutils/exceptions.py
@@ -30,16 +30,13 @@ class InvalidResponse(Error):
     """The response received from the meter was not understood"""
 
     def __init__(self, response):
-        super(InvalidResponse, self).__init__(
-            "Invalid response received:\n%s" % response
-        )
+        super(InvalidResponse, self).__init__(f"Invalid response received:\n{response}")
 
 
 class InvalidChecksum(InvalidResponse):
     def __init__(self, wire, calculated):
         super(InvalidChecksum, self).__init__(
-            "Response checksum not matching: %08x (wire) != %08x (calculated)"
-            % (wire, calculated)
+            f"Response checksum not matching: {wire:08x} (wire) != {calculated:08x} (calculated)"
         )
 
 
@@ -48,7 +45,7 @@ class InvalidGlucoseUnit(Error):
 
     def __init__(self, unit):
         super(InvalidGlucoseUnit, self).__init__(
-            "Invalid glucose unit received:\n%s" % unit
+            f"Invalid glucose unit received:\n{unit}"
         )
 
 
diff --git a/glucometerutils/glucometer.py b/glucometerutils/glucometer.py
index 012bdb1..31cfdc0 100755
--- a/glucometerutils/glucometer.py
+++ b/glucometerutils/glucometer.py
@@ -103,7 +103,7 @@ def main():
         driver = importlib.import_module("glucometerutils.drivers." + args.driver)
     except ImportError as e:
         logging.error(
-            'Error importing driver "%s", please check your --driver ' "parameter:\n%s",
+            'Error importing driver "%s", please check your --driver parameter:\n%s',
             args.driver,
             e,
         )
@@ -129,11 +129,7 @@ def main():
             # Also catch any leftover ValueErrors.
             except (NotImplementedError, ValueError):
                 time_str = "N/A"
-            print(
-                "{device_info}Time: {time}".format(
-                    device_info=str(device_info), time=time_str
-                )
-            )
+            print(f"{device_info}Time: {time_str}")
         elif args.action == "dump":
             unit = args.unit
             if unit is None:
@@ -179,7 +175,7 @@ def main():
                 patient_name = device.get_patient_name()
                 if patient_name is None:
                     patient_name = "[N/A]"
-                print("Patient Name: {patient_name}".format(patient_name=patient_name))
+                print(f"Patient Name: {patient_name}")
             except NotImplementedError:
                 print("The glucometer does not support retrieving patient name.")
         elif args.action == "zero":
@@ -193,7 +189,7 @@ def main():
         else:
             return 1
     except exceptions.Error as err:
-        print("Error while executing '%s': %s" % (args.action, str(err)))
+        print(f"Error while executing '{args.action}': {err}")
         return 1
 
     device.disconnect()
diff --git a/glucometerutils/support/contourusb.py b/glucometerutils/support/contourusb.py
index 3b0dc80..9afb79d 100644
--- a/glucometerutils/support/contourusb.py
+++ b/glucometerutils/support/contourusb.py
@@ -180,14 +180,14 @@ class ContourHidDevice(hiddevice.HidDevice):
 
         if recno != self.currecno:
             raise FrameError(
-                "Bad recno, got %r expected %r" % (recno, self.currecno), frame
+                f"Bad recno, got {recno!r} expected {self.currecno!r}", frame
             )
 
-        checksum = self.checksum(match.group("check"))
-        if checksum != match.group("checksum"):
+        calculated_checksum = self.checksum(match.group("check"))
+        received_checksum = match.group("checksum")
+        if calculated_checksum != received_checksum:
             raise FrameError(
-                "Checksum error: got %s expected %s"
-                % (match.group("checksum"), checksum),
+                f"Checksum error: received {received_checksum} expected {calculated_checksum}",
                 frame,
             )
 
diff --git a/glucometerutils/support/freestyle.py b/glucometerutils/support/freestyle.py
index 341e978..86c53d0 100644
--- a/glucometerutils/support/freestyle.py
+++ b/glucometerutils/support/freestyle.py
@@ -152,8 +152,7 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
         response = self._read_response()
         if not _is_init_reply(response):
             raise exceptions.ConnectionFailed(
-                "Connection error: unexpected message %02x:%s"
-                % (response[0], response[1].hex())
+                f"Connection error: unexpected message %{response[0]:02x}:{response[1].hex()}"
             )
 
     def disconnect(self):
@@ -235,8 +234,7 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
 
             if message_type != self.TEXT_REPLY_CMD:
                 raise exceptions.InvalidResponse(
-                    "Message type %02x does not match expectations: %r"
-                    % (message_type, content)
+                    f"Message type {message_type:02x}: content does not match expectations: {content!r}"
                 )
 
             full_content += content
@@ -317,10 +315,8 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
         # The format used by the FreeStyle devices is not composable based on
         # standard strftime() (namely it includes no leading zeros), so we need
         # to build it manually.
-        date_cmd = "$date,{month},{day},{year}".format(
-            month=date.month, day=date.day, year=(date.year - 2000)
-        )
-        time_cmd = "$time,{hour},{minute}".format(hour=date.hour, minute=date.minute)
+        date_cmd = f"$date,{date.month},{date.day},{date.year - 2000}"
+        time_cmd = f"$time,{date.hour},{date.minute}"
 
         self._send_text_command(bytes(date_cmd, "ascii"))
         self._send_text_command(bytes(time_cmd, "ascii"))
diff --git a/glucometerutils/support/hiddevice.py b/glucometerutils/support/hiddevice.py
index ad8f3a6..43461e7 100644
--- a/glucometerutils/support/hiddevice.py
+++ b/glucometerutils/support/hiddevice.py
@@ -52,9 +52,7 @@ class HidDevice:
         # If the user passed a device path that does not exist, raise an
         # error. This is to avoid writing to a file instead of to a device node.
         if device and not os.path.exists(device):
-            raise exceptions.ConnectionFailed(
-                message="Path %s does not exist." % device
-            )
+            raise exceptions.ConnectionFailed(message=f"Path {device} does not exist.")
 
         # If the user passed a device, try opening it.
         if device:
@@ -73,7 +71,7 @@ class HidDevice:
                 )
             except OSError as e:
                 raise exceptions.ConnectionFailed(
-                    message="Unable to connect to meter: %s." % e
+                    message=f"Unable to connect to meter: {e}."
                 )
 
     def _write(self, report):
diff --git a/glucometerutils/support/lifescan.py b/glucometerutils/support/lifescan.py
index 9340e49..1c329c6 100644
--- a/glucometerutils/support/lifescan.py
+++ b/glucometerutils/support/lifescan.py
@@ -11,7 +11,7 @@ class MissingChecksum(exceptions.InvalidResponse):
 
     def __init__(self, response):
         super(MissingChecksum, self).__init__(
-            "Response is missing checksum: %s" % response
+            f"Response is missing checksum: {response}"
         )
 
 
@@ -20,13 +20,13 @@ class InvalidSerialNumber(exceptions.Error):
 
     def __init__(self, serial_number):
         super(InvalidSerialNumber, self).__init__(
-            "Serial number %s is invalid." % serial_number
+            f"Serial number {serial_number} is invalid."
         )
 
 
 class MalformedCommand(exceptions.InvalidResponse):
     def __init__(self, message):
-        super(MalformedCommand, self).__init__("Malformed command: %s" % message)
+        super(MalformedCommand, self).__init__(f"Malformed command: {message}")
 
 
 def crc_ccitt(data):
diff --git a/reversing_tools/abbott/freestyle_hid_console.py b/reversing_tools/abbott/freestyle_hid_console.py
index 5005e4a..654a97c 100755
--- a/reversing_tools/abbott/freestyle_hid_console.py
+++ b/reversing_tools/abbott/freestyle_hid_console.py
@@ -56,12 +56,12 @@ def main():
             command = input(">>> ")
         else:
             command = input()
-            print(">>> {command}".format(command=command))
+            print(f">>> {command}")
 
         try:
             print(device._send_text_command(bytes(command, "ascii")))
         except exceptions.InvalidResponse as error:
-            print("! {error}".format(error=error))
+            print(f"! {error}")
 
 
 if __name__ == "__main__":