homepage

Actually it should be:
 # Using zlib's interface
 while not d.eof:
 output = d.decompress(d.unconsumed_tail, 8192)
 while not output and not d.eof:
 compressed = f.read(8192)
 if not compressed:
 raise ValueError('End-of-stream marker not found')
 output = d.decompress(d.unconsumed_tail + compressed, 8192)
 # <process output>
Note that you should use d.unconsumed_tail + compressed as input, and therefore do an unnecessary copy of the data.
Without explicit unconsumed_tail you can write input data in the internal mutable buffer, it will be more effective for large buffer (handreds of KB) and small input chunks (several KB).