Python read text file as binary?

Even when reading a file with the 'rb' flag, if your file has the byte '\x41' it will be printed as the letter 'A' in the console. If you want the hex values, encode the file content as hex, which means:

content = open('text.txt', 'rb').read()
# Since python 3.5:
hex = content.hex()
# else:
hex = content.encode('hex')

Take a look at below code .also it has many points for you

from hashlib import md5
from Crypto.Cipher import AES
from Crypto import Random

def derive_key_and_iv(password, salt, key_length, iv_length):
    d = d_i = ''
    while len(d) < key_length + iv_length:
        d_i = md5(d_i + password + salt).digest()
        d += d_i
    return d[:key_length], d[key_length:key_length+iv_length]

def encrypt(in_file, out_file, password, key_length=32):
    bs = AES.block_size
    salt = Random.new().read(bs - len('Salted__'))
    key, iv = derive_key_and_iv(password, salt, key_length, bs)
    cipher = AES.new(key, AES.MODE_CBC, iv)
    out_file.write('Salted__' + salt)
    finished = False
    while not finished:
        chunk = in_file.read(1024 * bs)
        if len(chunk) == 0 or len(chunk) % bs != 0:
            padding_length = (bs - len(chunk) % bs) or bs
            chunk += padding_length * chr(padding_length)
            finished = True
        out_file.write(cipher.encrypt(chunk))

def decrypt(in_file, out_file, password, key_length=32):
    bs = AES.block_size
    salt = in_file.read(bs)[len('Salted__'):]
    key, iv = derive_key_and_iv(password, salt, key_length, bs)
    cipher = AES.new(key, AES.MODE_CBC, iv)
    next_chunk = ''
    finished = False
    while not finished:
        chunk, next_chunk = next_chunk, cipher.decrypt(in_file.read(1024 * bs))
        if len(next_chunk) == 0:
            padding_length = ord(chunk[-1])
            chunk = chunk[:-padding_length]
            finished = True
        out_file.write(chunk)

Usage

with open(in_filename, 'rb') as in_file, open(out_filename, 'wb') as out_file:
    encrypt(in_file, out_file, password)
with open(in_filename, 'rb') as in_file, open(out_filename, 'wb') as out_file:
    decrypt(in_file, out_file, password)

Your binary file is coming out looking like text because the file is being treated like it is encoded in an 8 bit encoding (ASCII or Latin-1, etc). Also, in Python 2, bytes and (text) characters are used interchangeably... i.e. a string is just an array of ASCII bytes.

You should search the differences between python 2 and 3 text encoding and you will quickly see why anomalies such as you are encountering can develop. Most of the Python 2 version encryption modules use the python byte strings.

Your "binary" non-text files are not really being treated any differently from the text ones; they just don't map to an intelligible coding that you recognize, whereas the text ones do.