fname = "secret.txt" with open(fname, "r", encoding="utf-8") as file: for line in file: string = line.rstrip("\n") res = '' for char in string: b = bin(ord(char))[2:] if len(b) % 8 != 0: bytenum = len(b) // 8 + 1 b = "0" * (8 * bytenum - len(b)) + b if len(b) <= 8: res += chr(int(b, 2)) else: res += chr(int(b[8:], 2)) print(res)