具有自定义派生数量的 KeyError

Question

我用

定义了一个新的派生维度

[molar_energy] = [energy] / [substance]

但是，如果我执行以下操作，它会抱怨：

>>> UR.get_compatible_units('[molar_energy]')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/cedric/.local/share/virtualenvs/MatDB--uGOYMXa/lib/python3.9/site-packages/pint/registry.py", line 881, in get_compatible_units
    equiv = self._get_compatible_units(input_units, group_or_system)
  File "/Users/cedric/.local/share/virtualenvs/MatDB--uGOYMXa/lib/python3.9/site-packages/pint/registry.py", line 2082, in _get_compatible_units
    ret = super()._get_compatible_units(input_units, group_or_system)
  File "/Users/cedric/.local/share/virtualenvs/MatDB--uGOYMXa/lib/python3.9/site-packages/pint/registry.py", line 1835, in _get_compatible_units
    ret = super()._get_compatible_units(input_units, group_or_system)
  File "/Users/cedric/.local/share/virtualenvs/MatDB--uGOYMXa/lib/python3.9/site-packages/pint/registry.py", line 891, in _get_compatible_units
    return self._cache.dimensional_equivalents[src_dim]
KeyError: <UnitsContainer({'[length]': 2, '[mass]': 1, '[substance]': -1, '[time]': -2})

我看到上下文中包含一个转换，但我没有使用它。我做错了什么？

感谢您的帮助

PS：记录问题 https://github.com/hgrecco/pint/issues/1418

Answer 1

这里只为遇到此问题的任何人留下解决方案。

我刚刚添加了一个自制单元并且它起作用了

# Molar Energy
[molar_energy] = [energy] / [substance]
mol_en = J / mol

具有自定义派生数量的 KeyError

KeyError with custom derived quantity

python

pint