Merge pull request #8 from Nakakiyo092/feature/refactoring

Refactoring code

Author: Nakakiyo092

reader/reader.py

@@ -1,16 +1,27 @@
 #!/usr/bin/env python3
 
+"""
+A Python script to retreive Event Data Recorder (EDR) data via CAN bus
+according to the Chinese standard GB39732-2020.
+
+License:
+    MIT License.
+    See the accompanying LICENSE file for full terms.
+"""
+
 import os
 import shutil
+import sys
 import time
 import csv
 
 import can
 import isotp
-from udsoncan import Request, Response
+from udsoncan import Response
 from udsoncan.services import ReadDataByIdentifier
 
 def read_did(did, bus, notifier, tx_addr, rx_addrs, addr_type, isotp_params) -> bytearray:
+    """Read one data by identifier (DID) from the target ECU."""
 
     print("")
     if tx_addr.is_tx_29bits():
@@ -21,19 +32,35 @@ def read_did(did, bus, notifier, tx_addr, rx_addrs, addr_type, isotp_params) ->
         print("Reading data id", hex(did), "with 11bits physical address.")
 
     # Setup ISOTP stacks
-    tx_stack = isotp.NotifierBasedCanStack(bus=bus, notifier=notifier, address=tx_addr, params=isotp_params)
+    tx_stack = isotp.NotifierBasedCanStack(
+        bus=bus,
+        notifier=notifier,
+        address=tx_addr,
+        params=isotp_params
+        )
     rx_stacks = []
     rx_stacks.append(tx_stack)  # Add tx_stack itself to support Physical addressing
     for rx_addr in rx_addrs:
-        rx_stack = isotp.NotifierBasedCanStack(bus=bus, notifier=notifier, address=rx_addr, params=isotp_params)
+        rx_stack = isotp.NotifierBasedCanStack(
+            bus=bus, notifier=notifier,
+            address=rx_addr,
+            params=isotp_params
+            )
         rx_stacks.append(rx_stack)
 
     # Request message
     request = ReadDataByIdentifier.make_request(didlist=[did], didconfig={'default':'s'})
 
     # Response message (positive/pending)
-    response = Response(service=ReadDataByIdentifier, code=Response.Code.PositiveResponse, data=bytes([(did>>8)&0xFF,did&0xFF]))
-    pend_response = Response(service=ReadDataByIdentifier, code=Response.Code.RequestCorrectlyReceived_ResponsePending)
+    response = Response(
+        service=ReadDataByIdentifier,
+        code=Response.Code.PositiveResponse,
+        data=bytes([(did>>8)&0xFF,did&0xFF])
+        )
+    pend_response = Response(
+        service=ReadDataByIdentifier,
+        code=Response.Code.RequestCorrectlyReceived_ResponsePending
+        )
 
     # Start stacks
     for rx_stack in rx_stacks:
@@ -84,15 +111,17 @@ def read_did(did, bus, notifier, tx_addr, rx_addrs, addr_type, isotp_params) ->
 
 
 def output_data(payload) -> bytearray:
+    """Output the data to a CSV file according to the format defined in the 'format' folder."""
+
     # Get target did from payload
     if payload is None:
-        print(f"No data to output.")
+        print("No data to output.")
         return
-    elif len(payload) < 3:
-        print(f"The payload is too short.")
+    if len(payload) < 3:
+        print("The payload is too short.")
         return
-    else:
-        did = f"{payload[1]:02x}{payload[2]:02x}"
+
+    did = f"{payload[1]:02x}{payload[2]:02x}"
 
     # File paths for source and destination
     source_file = "format/did_" + did + ".csv"
@@ -117,15 +146,18 @@ def output_data(payload) -> bytearray:
 
     # Read the input CSV file and write to the output file with the additional column
     try:
-        with open(source_file, mode="r", encoding="utf-8") as infile, open(destination_file, mode="w", encoding="utf-8", newline="") as outfile:
+        with (
+            open(source_file, mode="r", encoding="utf-8") as infile,
+            open(destination_file, mode="w", encoding="utf-8", newline="") as outfile
+        ):
             reader = csv.reader(infile)
             writer = csv.writer(outfile)
-            
+
             # Read header and add new column name
             header = next(reader)
             header.append("Raw value")  # Add a new column named 'Raw value'
             writer.writerow(header)
-            
+
             # Process rows
             for row in reader:
                 no = int(row[0])  # Convert No column to integer
@@ -134,7 +166,7 @@ def output_data(payload) -> bytearray:
                 else:
                     row.append("N/A")  # Handle cases where No is out of range
                 writer.writerow(row)
-        
+
     except FileNotFoundError:
         print(f"The file '{source_file}' or '{destination_file}' does not exist.")
         return
@@ -153,7 +185,7 @@ def output_data(payload) -> bytearray:
     #bus = can.Bus('test', interface='virtual')
 except Exception as err:
     print(err)
-    exit()
+    sys.exit()
 
 # Setup a debug listener that print all messages
 #notifier = can.Notifier(bus, [can.Printer()])
@@ -162,22 +194,41 @@ def output_data(payload) -> bytearray:
 
 # Isotp parameters
 isotp_params = {
- 'stmin': 0,                             # Will request the sender to wait 0ms between consecutive frame. 0-127ms or 100-900ns with values from 0xF1-0xF9
- 'blocksize': 0,                         # Request the sender to send all consecutives frames without waiting a new flow control message
- 'wftmax': 0,                            # Number of wait frame allowed before triggering an error
- 'tx_data_length': 8,                    # Link layer (CAN layer) works with 8 byte payload (CAN 2.0)
- 'tx_data_min_length': 8,                # Minimum length of CAN messages. Messages are padded to meet this length.
- 'tx_padding': 0,                        # Will pad all transmitted CAN messages with byte 0x00.
- 'rx_flowcontrol_timeout': 1000,         # Triggers a timeout if a flow control is awaited for more than 1000 milliseconds
- 'rx_consecutive_frame_timeout': 1000,   # Triggers a timeout if a consecutive frame is awaited for more than 1000 milliseconds
- 'override_receiver_stmin': None,        # When sending, respect the stmin requirement of the receiver. Could be set to a float value in seconds.
- 'max_frame_size': 4095,                 # Limit the size of receive frame.
- 'can_fd': False,                        # Does not set the can_fd flag on the output CAN messages
- 'bitrate_switch': False,                # Does not set the bitrate_switch flag on the output CAN messages
- 'rate_limit_enable': False,             # Disable the rate limiter
- 'rate_limit_max_bitrate': 1000000,      # Ignored when rate_limit_enable=False. Sets the max bitrate when rate_limit_enable=True
- 'rate_limit_window_size': 0.2,          # Ignored when rate_limit_enable=False. Sets the averaging window size for bitrate calculation when rate_limit_enable=True
- 'listen_mode': False,                   # Does not use the listen_mode which prevent transmission.
+    # Will request the sender to wait 0ms between consecutive frame.
+    # 0-127ms or 100-900ns with values from 0xF1-0xF9.
+    'stmin': 0,
+    # Request the sender to send all consecutives frames without waiting a new flow control message.
+    'blocksize': 0,
+    # Number of wait frame allowed before triggering an error.
+    'wftmax': 0,
+    # Link layer (CAN layer) works with 8 byte payload (CAN 2.0).
+    'tx_data_length': 8,
+    # Minimum length of CAN messages. Messages are padded to meet this length.
+    'tx_data_min_length': 8,
+    # Will pad all transmitted CAN messages with byte 0x00.
+    'tx_padding': 0,
+    # Triggers a timeout if a flow control is awaited for more than 1000 milliseconds.
+    'rx_flowcontrol_timeout': 1000,
+    # Triggers a timeout if a consecutive frame is awaited for more than 1000 milliseconds.
+    'rx_consecutive_frame_timeout': 1000,
+    # When sending, respect the stmin requirement of the receiver.
+    # Could be set to a float value in seconds.
+    'override_receiver_stmin': None,
+    # Limit the size of receive frame.
+    'max_frame_size': 4095,
+    # Does not set the can_fd flag on the output CAN messages.
+    'can_fd': False,
+    # Does not set the bitrate_switch flag on the output CAN messages.
+    'bitrate_switch': False,
+    # Disable the rate limiter.
+    'rate_limit_enable': False,
+    # Ignored when rate_limit_enable=False. Sets the max bitrate when rate_limit_enable=True.
+    'rate_limit_max_bitrate': 1000000,
+    # Ignored when rate_limit_enable=False.
+    # Sets the averaging window size for bitrate calculation when rate_limit_enable=True.
+    'rate_limit_window_size': 0.2,
+    # Does not use the listen_mode which prevent transmission.
+    'listen_mode': False,
 }
 
 
@@ -189,11 +240,12 @@ def output_data(payload) -> bytearray:
     rx_addrs.append(rx_addr)
 
 try:
-    payload = read_did(0xfa13, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Functional, isotp_params)
+    func = isotp.TargetAddressType.Functional
+    payload = read_did(0xfa13, bus, notifier, tx_addr, rx_addrs, func, isotp_params)
     output_data(payload)
-    payload = read_did(0xfa14, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Functional, isotp_params)
+    payload = read_did(0xfa14, bus, notifier, tx_addr, rx_addrs, func, isotp_params)
     output_data(payload)
-    payload = read_did(0xfa15, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Functional, isotp_params)
+    payload = read_did(0xfa15, bus, notifier, tx_addr, rx_addrs, func, isotp_params)
     output_data(payload)
 except Exception as err:
     print(err)
@@ -204,30 +256,40 @@ def output_data(payload) -> bytearray:
 rx_addrs = []
 
 try:
-    payload = read_did(0xfa13, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Physical, isotp_params)
+    phys = isotp.TargetAddressType.Physical
+    payload = read_did(0xfa13, bus, notifier, tx_addr, rx_addrs, phys, isotp_params)
     output_data(payload)
-    payload = read_did(0xfa14, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Physical, isotp_params)
+    payload = read_did(0xfa14, bus, notifier, tx_addr, rx_addrs, phys, isotp_params)
     output_data(payload)
-    payload = read_did(0xfa15, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Physical, isotp_params)
+    payload = read_did(0xfa15, bus, notifier, tx_addr, rx_addrs, phys, isotp_params)
     output_data(payload)
 except Exception as err:
     print(err)
 
 
 # Read with 29bits address
-tx_addr = isotp.Address(isotp.AddressingMode.NormalFixed_29bits, target_address=0xFF, source_address=0xF1)
+tx_addr = isotp.Address(
+    isotp.AddressingMode.NormalFixed_29bits,
+    target_address=0xFF,
+    source_address=0xF1
+    )
 rx_addrs = []
 for i in range(0xF0):
     if i != 0x33:
-        rx_addr = isotp.Address(isotp.AddressingMode.NormalFixed_29bits, target_address=i, source_address=0xF1)
+        rx_addr = isotp.Address(
+            isotp.AddressingMode.NormalFixed_29bits,
+            target_address=i,
+            source_address=0xF1
+            )
         rx_addrs.append(rx_addr)
 
 try:
-    payload = read_did(0xfa13, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Functional, isotp_params)
+    func = isotp.TargetAddressType.Functional
+    payload = read_did(0xfa13, bus, notifier, tx_addr, rx_addrs, func, isotp_params)
     output_data(payload)
-    payload = read_did(0xfa14, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Functional, isotp_params)
+    payload = read_did(0xfa14, bus, notifier, tx_addr, rx_addrs, func, isotp_params)
     output_data(payload)
-    payload = read_did(0xfa15, bus, notifier, tx_addr, rx_addrs, isotp.TargetAddressType.Functional, isotp_params)
+    payload = read_did(0xfa15, bus, notifier, tx_addr, rx_addrs, func, isotp_params)
     output_data(payload)
 except Exception as err:
     print(err)
@@ -237,7 +299,7 @@ def output_data(payload) -> bytearray:
 try:
     shutil.copy("format/README.md", "result/README.md")
 except FileNotFoundError:
-    print(f"The source file format/README.md does not exist.")
+    print("The source file format/README.md does not exist.")
 except PermissionError:
     print("You do not have the necessary permissions to read or write the file.")
 except Exception as err: