Edit Intel HEX file

__main__.py

from intelhex import IntelHex
from pathlib import Path


FILE_IN = Path('./in.hex')
FILE_OUT = Path('./out.hex')

# Open HEX file, replace a byte and save in a new HEX file.
# https://python-intelhex.readthedocs.io/en/latest/part2-2.html
ih = IntelHex()
with open(FILE_IN) as in_, open(FILE_OUT, 'w') as out:
	ih.fromfile(in_, format='hex')  # read
	# NOTE: Replace first byte.
	ih[0] = 0x55

	ih.tofile(out, format='hex')  # or `ih.write_hex_file(out)`