1# Inspired from https://construct.readthedocs.io/en/latest/intro.html#example
2import construct
3
4format = construct.Struct(
5    "signature" / construct.Const(b"BMP"),
6    "width" / construct.Int8ub,
7    "height" / construct.Int8ub,
8    "pixels" / construct.Array(construct.this.width * construct.this.height, construct.Byte),
9)
10a = format.build(dict(width=3,height=2,pixels=[7,8,9,11,12,13]))
11assert(a == b'BMP\x03\x02\x07\x08\t\x0b\x0c\r')
12b = format.parse(b'BMP\x03\x02\x07\x08\t\x0b\x0c\r')
13assert(b.signature == b'BMP')
14assert(b.width == 3)
15assert(b.height == 2)
16assert(b.pixels == [7, 8, 9, 11, 12, 13])
17