Extract zlib compressed data from binary file in python

Question

My company uses a legacy file format for Electromiography data, which is no longer in production. However, there is some interest in maintaining retro-compatibility, so I am

Answer 1

To start, why not scan the files for all valid zip streams (it's good enough for small files and to figure out the format):

import zlib
from glob import glob

def zipstreams(filename):
    """Return all zip streams and their positions in file."""
    with open(filename, 'rb') as fh:
        data = fh.read()
    i = 0
    while i < len(data):
        try:
            zo = zlib.decompressobj()
            yield i, zo.decompress(data[i:])
            i += len(data[i:]) - len(zo.unused_data)
        except zlib.error:
            i += 1

for filename in glob('*.mio'):
    print(filename)
    for i, data in zipstreams(filename):
        print (i, len(data))

Looks like the data streams contain little-endian double precision floating point data:

import numpy
from matplotlib import pyplot

for filename in glob('*.mio'):
    for i, data in zipstreams(filename):
        if data:
            a = numpy.fromstring(data, '