bitmath simplifies many facets of interacting with file sizes in various units.
Functionality includes:

- Converting between SI and NIST prefix units (kB to GiB)
- Converting between units of the same type (SI to SI, or NIST to NIST)
- Automatic human-readable prefix selection (like in hurry.filesize)
- Basic arithmetic operations (subtracting 42KiB from 50GiB)
- Rich comparison operations (1024 Bytes == 1KiB)
- bitwise operations (<<, >>, &, |, ^)
- argparse integration
- progressbar integration
- String parsing
- Sorting

WWW: https://github.com/tbielawa/bitmath