| #!/usr/bin/env python |
| |
| """ |
| Byte packing and unpacking utilities. |
| |
| Copyright (C) 2017-2020 Cosmin Truta. |
| |
| Use, modification and distribution are subject to the MIT License. |
| Please see the accompanying file LICENSE_MIT.txt |
| """ |
| |
| from __future__ import absolute_import, division, print_function |
| |
| import struct |
| |
| |
| def unpack_uint32be(buffer, offset=0): |
| """Unpack an unsigned int from its 32-bit big-endian representation.""" |
| return struct.unpack(">I", buffer[offset:offset + 4])[0] |
| |
| |
| def unpack_uint32le(buffer, offset=0): |
| """Unpack an unsigned int from its 32-bit little-endian representation.""" |
| return struct.unpack("<I", buffer[offset:offset + 4])[0] |
| |
| |
| def unpack_uint16be(buffer, offset=0): |
| """Unpack an unsigned int from its 16-bit big-endian representation.""" |
| return struct.unpack(">H", buffer[offset:offset + 2])[0] |
| |
| |
| def unpack_uint16le(buffer, offset=0): |
| """Unpack an unsigned int from its 16-bit little-endian representation.""" |
| return struct.unpack("<H", buffer[offset:offset + 2])[0] |
| |
| |
| def unpack_uint8(buffer, offset=0): |
| """Unpack an unsigned int from its 8-bit representation.""" |
| return struct.unpack("B", buffer[offset:offset + 1])[0] |
| |
| |
| if __name__ == "__main__": |
| # For testing only. |
| assert unpack_uint32be(b"ABCDEF", 1) == 0x42434445 |
| assert unpack_uint32le(b"ABCDEF", 1) == 0x45444342 |
| assert unpack_uint16be(b"ABCDEF", 1) == 0x4243 |
| assert unpack_uint16le(b"ABCDEF", 1) == 0x4342 |
| assert unpack_uint8(b"ABCDEF", 1) == 0x42 |
