turn a zip file into a prime number

prime-zipper.py

import sympy as sp
	
fileName = "file.zip"

with open(fileName, mode="rb") as file:
	fileContents = bytearray(file.read())
	fileContents.append(255)
	while not sp.isprime(int.from_bytes(fileContents)):
		if (int.from_bytes(fileContents[-1:]) != 0):
			print("bruteforcing " + str(int.from_bytes(fileContents[-1:])))
			fileContents[-1:] = [int.from_bytes(fileContents[-1:]) - 1]
		else:
			print("appending")
			fileContents.append(255)
	print("prime detected")
	print(int.from_bytes(fileContents))
	with open("file-prime.zip", "wb") as outFile:
		outFile.write(fileContents)

this is very slow, don't use it on anything more than a couple bytes