Convert pcapng with CAN messages to CAN log

pcapng2log.py

import struct
import argparse
import pcapng.blocks
from pcapng import FileScanner

def unpackCANFrame(frame,reverse=False):
  #https://github.com/hardbyte/python-can/blob/ae0bc1746c04b3c1ccd8b56aba99895d50c87d2d/can/interfaces/socketcan/socketcan.py#L511
  CAN_FRAME_HEADER_STRUCT = struct.Struct(">IBB2x") if reverse == False else struct.Struct("=IBB2x")
  can_id, can_dlc, flags = CAN_FRAME_HEADER_STRUCT.unpack_from(frame)
  data = frame[8 : 8 + can_dlc]
  arbitration_id = '%08x'%(can_id & 0x1FFFFFFF) if bool(can_id & 0x80000000) else '%03x'%(can_id & 0x000007FF)
  return arbitration_id, data.hex()
  
  
parser = argparse.ArgumentParser(description='Convert pcapng with CAN messages to CAN log')
parser.add_argument('FILE', metavar='FILE', type=str, help='File path')
FILE = parser.parse_args().FILE
                    
with open(FILE,'rb') as f:
    scanner = FileScanner(f)
    blocks = [block for block in scanner if type(block)==pcapng.blocks.EnhancedPacket]
    
with open(FILE[:-7]+'.log','w') as f:
  for block in blocks:
    arbitration_id, data = unpackCANFrame(block.packet_data)
    line = '(%.6f) %s %s#%s\n'%(block.timestamp,block.interface.options['if_name'],arbitration_id,data)
    print(line)
    f.write(line)
    f.flush()