Python classes ? being pythonic

def __init__(self, value, unit='kg'): if not isinstance(value, (int, float)) or isinstance(value, bool): raise ValueError("Value must be a number") if value < 0: raise MassLessThanZeroException("Value cannot be negative") if unit not in self._conversion: raise UnitNotDefinedException("Unit cannot be used") self.value = value self.unit = unit def convert_to_kg(self): return self.value * Mass._conversion[self.unit] def __str__(self): return f"{self.convert_to_kg():.2f} kg" def __repr__(self): return f"Mass({self.value:.2f}, '{self.unit}')" def __add__(self, other): if isinstance(other, (int, float)): total = self.convert_to_kg() + other else: total = self.convert_to_kg() + other.convert_to_kg() return Mass(total / Mass._conversion[self.unit], self.unit) def __iadd__(self, other): return self + other def __radd__(self, other): return self + other def __sub__(self, other): if isinstance(other, (int, float)): total = self.convert_to_kg() - other else: total = self.convert_to_kg() - other.convert_to_kg() return Mass(max(0, total) / Mass._conversion[self.unit], self.unit) def __isub__(self, other): return self - other def __rsub__(self, other): if isinstance(other, (int, float)): total = other - self.convert_to_kg() else: total = other.convert_to_kg() - self.convert_to_kg() return Mass(max(0, total) / Mass._conversion[self.unit], self.unit) def __lt__(self, other): return self.convert_to_kg() < other.convert_to_kg() def __gt__(self, other): return self.convert_to_kg() > other.convert_to_kg() def __eq__(self, other): return abs(self.convert_to_kg() - other.convert_to_kg()) < 0.01