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DimensionalityError Traceback (most recent call last)
<ipython-input-20-aa3a0fa3be0b> in <module>()
----> 1 print P.to(ur.gallon)
/Users/jeff/anaconda/lib/python2.7/site-packages/pint/quantity.pyc in to(self, other, *contexts, **ctx_kwargs)
241 other = UnitsContainer(other)
242
--> 243 magnitude = self._convert_magnitude_not_inplace(other, *contexts, **ctx_kwargs)
244
245 return self.__class__(magnitude, other)
/Users/jeff/anaconda/lib/python2.7/site-packages/pint/quantity.pyc in _convert_magnitude_not_inplace(self, other, *contexts, **ctx_kwargs)
196 return self._REGISTRY.convert(self._magnitude, self._units, other)
197
--> 198 return self._REGISTRY.convert(self._magnitude, self._units, other)
199
200 def _convert_magnitude(self, other, *contexts, **ctx_kwargs):
/Users/jeff/anaconda/lib/python2.7/site-packages/pint/unit.pyc in convert(self, value, src, dst, inplace)
1039
1040 if src_dim != dst_dim:
-> 1041 raise DimensionalityError(src, dst, src_dim, dst_dim)
1042
1043 # Conversion needs to consider if non-multiplicative (AKA offset
DimensionalityError: Cannot convert from 'pascal' ([mass] / [length] / [time] ** 2) to 'gallon' ([length] ** 3)