用Python读取二进制文件并将其写入第三个文件中非零字节的另一个补丁中

Question

In Python-3.x which is the best way to patch binary file with nonzero bytes from another (creating third output file), all of course keeping original byte sequence?

Just to read out source file and patch file and write source byte-by-byte is not a problem, but how to parse both of them byte-by-byte:

    output = open('File3', 'wb')
    patch = open('File2', "rb").read()
    with open('File1', 'rb') as f:
        bytei = f.read(1)
        while bytei != b"":
            output.write(bytei)
            bytei = f.read(1)

All files are small <50kb, speed isn't issue.

Answer 1

If I have understood correctly, then the following is what you are attempting to do:

from itertools import zip_longest

with open('File1', 'rb') as f1, \
    open('File2', 'rb') as f2, \
    open('File3', 'wb') as f3:

    output = bytearray()

    for v1, v2 in zip_longest(f1.read(), f2.read()):
        output.append(v2 if v2 else v1)

    f3.write(output)

For example:

File1 01 02 03 04 05 06 07 08 09 0a 00
File2 00 11 00 00 14 00 16

Gives:

File3 01 11 03 04 14 06 16 08 09 0a 00