try: import zlib except ImportError: import uzlib as zlib import uio as io # Raw DEFLATE bitstream buf = io.BytesIO(b'\xcbH\xcd\xc9\xc9\x07\x00') inp = zlib.DecompIO(buf, -8) print(buf.seek(0, 1)) print(inp.read(1)) print(buf.seek(0, 1)) print(inp.read(2)) print(inp.read()) print(buf.seek(0, 1)) print(inp.read(1)) print(inp.read()) print(buf.seek(0, 1)) # zlib bitstream inp = zlib.DecompIO(io.BytesIO(b'x\x9c30\xa0=\x00\x00\xb3q\x12\xc1')) print(inp.read(10)) print(inp.read()) # zlib bitstream, wrong checksum inp = zlib.DecompIO(io.BytesIO(b'x\x9c30\xa0=\x00\x00\xb3q\x12\xc0')) try: print(inp.read()) except OSError as e: print(repr(e))