This should be closed as the zlib module is not an expected part of the stdlib, and this issue is because Windows uses a packaged version of the zlib C library whereas Linux can use others. I presume they both work in decompression?

you can test it yourself! presume what?

By passing zlib.MAX_WBITS | 16 the wbits value is 31. According to the docs:

+25 to +31 = 16 + (9 to 15): Uses the low 4 bits of the value as the window size logarithm, while including a basic gzip header and trailing checksum in the output.

Emphasis mine. Per the gzip spec, the 9th byte in the header is the OS marker:

This identifies the type of file system on which compression took place

So I believe that the code is working as intended. If you want just a zlib stream, you probably want to remove the | 16. If you want a GZip stream, you need to normalize the OS byte after calling zlib.compress.

By passing zlib.MAX_WBITS | 16 the wbits value is 31. According to the docs:

+25 to +31 = 16 + (9 to 15): Uses the low 4 bits of the value as the window size logarithm, while including a basic gzip header and trailing checksum in the output.

Emphasis mine. Per the gzip spec, the 9th byte in the header is the OS marker:

This identifies the type of file system on which compression took place

So I believe that the code is working as intended. If you want just a zlib stream, you probably want to remove the | 16. If you want a GZip stream, you need to normalize the OS byte after calling zlib.compress.

Thanks, but i use javascript or nodejs in in different systems, it work the same result. this make me in trouble...

I'm going to close this since zlib is working as intended.

A potential solution to make a gzip output that is OS independent would be along the lines of:

def zip(e):
    if isinstance(e, str):
        e = e.encode('utf-8')
    b = bytearray(zlib.compress(e, zlib.Z_DEFAULT_COMPRESSION, zlib.MAX_WBITS | 16))
    b[9] = 255 # unknown OS, for compatibility, could also set to 3, for UNIX
    return bytes(b)

Note that the GZip format includes other metadata that is not reproducible such as the mtime field, so the above solution may not be complete.