A parser for mathematical expressions with units, written in pure Python 3. It takes a string as input and returns the number that it represents, including any unit. A given expression can also be expressed in terms of another one, resulting in an numerical value.

All allowed units a read from a configuration file, that can be easily extended. Additional mathematical expressions can also be added. The default config supports only SI units.

It also comes with a simple curses based interfaced, that can be used as a simple calculator.

Minimal example:

$ python3
>>> import unitparser
>>> unitparser.in_units_of("3m+4mm", "cm")
300.4
>>> unitparser.in_units_of("c", "km/s")
299792.458

For a more detailed example, see unitparser/example.py

To install system wide, add these lines to your .bashrc:

export PYTHONPATH=path/to/repository:$PYTHONPATH
alias units='python3 -c "from unitparser import ui; ui.main()"'

Afterwards type units to launch the UI.

This project licensed under the GNU General Public License v3.