A Python package for handling chemical formulae for atoms, isotopes, molecules and isotopologues.
A very quick overview:
In [1]: from pyvalem.chem_formula import ChemFormula
In [2]: ethanol = ChemFormula('CH3CH2OH')
In [3]: ethanol.rmm
Out[3]: 46.068439999999995
In [4]: ethanol.stoichiometric_formula()
Out[4]: 'H6C2O'
In [5]: ethanol.stoichiometric_formula('alphabetical')
Out[5]: 'C2H6O'
In [6]: ethanol.stoichiometric_formula('hill')
Out[6]: 'C2H6O'
In [7]: ethanol.html
Out[7]: 'CH<sub>3</sub>CH<sub>2</sub>OH'
In [8]: ethanol.slug
Out[8]: 'CH3CH2OH'
In [9]: ethanol.natoms
Out[9]: 9
In [10]: ethanol.charge
Out[10]: 0
For more information and examples, see http://christianhill.co.uk/projects/pyvalem