gistfile1.py

def output_plain(buf):
    sizes = [28, 24, 20, 16, 12, 8, 4, 3, 2, 1]
    
    while len(buf):
        for size in sizes:
            if size <= len(buf):
                data = buf[:size]
                if size < 4:
                    yield pack('<B', 0xfc + len(data)) + data
                else:
                    yield pack('<B', 0xe0 | ((len(data) - 4) >> 2)) + data                
                
                buf = buf[size:]
                break