Magcard Write Read Utility Program ●

def read_track(self, track_num): if track_num == 1: return self.track1 elif track_num == 2: return self.track2 elif track_num == 3: return self.track3 else: raise ValueError("Track must be 1, 2, or 3")

TRACK_MAX_LEN = 1: 79, 2: 40, 3: 107 class MagCard: def init (self): self.track1 = "" self.track2 = "" self.track3 = "" magcard write read utility program

python magcard_util.py --read 1 | Feature | Description | |--------|-------------| | ISO 7811 compliance | Enforces valid character sets and max lengths per track. | | Sentinel & LRC | Simulates magnetic stripe encoding with start/end sentinels and XOR checksum. | | Read/Write abstraction | Easy to replace MagCard class with real hardware driver (serial/HID). | | Error handling | Prevents invalid data from being written. | Extending to real hardware To use actual magnetic stripe readers/writers (e.g., MagTek, IDTECH, HID Omnikey), replace the MagCard class methods with device-specific commands – typically via serial or pyusb . def read_track(self, track_num): if track_num == 1: return

def clear(self): self.track1 = "" self.track2 = "" self.track3 = "" def encode_track(data, start_sentinel='%', end_sentinel='?'): """Adds start/end sentinels and LRC (simple XOR checksum)""" lrc = 0 for ch in data: lrc ^= ord(ch) checksum_char = chr(lrc % 128) # simple printable approximation return f"start_sentineldataend_sentinelchecksum_char" | | Error handling | Prevents invalid data

def interactive_write(card): track = int(input("Enter track to write (1/2/3): ")) data = input(f"Enter data for track track (max TRACK_MAX_LEN[track] chars): ").strip() try: card.write_track(track, data) print(f"Track track written successfully.") except ValueError as e: print(f"Write failed: e")