平衡化學反應的化學計量

 from chempy import balance_stoichiometry  # Main reaction in NASA's booster rockets:
 reac, prod = balance_stoichiometry({'NH4ClO4', 'Al'}, {'Al2O3', 'HCl', 'H2O', 'N2'})
 from pprint import pprint
 pprint(reac)
{'Al': 10, 'NH4ClO4': 6}
 pprint(prod)
{'Al2O3': 5, 'H2O': 9, 'HCl': 6, 'N2': 3}
 from chempy import mass_fractions
 for fractions in map(mass_fractions, [reac, prod]):
...     pprint({k: '{0:.3g} wt%'.format(v*100) for k, v in fractions.items()})
...
{'Al': '27.7 wt%', 'NH4ClO4': '72.3 wt%'}
{'Al2O3': '52.3 wt%', 'H2O': '16.6 wt%', 'HCl': '22.4 wt%', 'N2': '8.62 wt%'}