from peewee import ModelDescriptor # Hybrid methods/attributes, based on similar functionality in SQLAlchemy: # http://docs.sqlalchemy.org/en/improve_toc/orm/extensions/hybrid.html class hybrid_method(ModelDescriptor): def __init__(self, func, expr=None): self.func = func self.expr = expr or func def __get__(self, instance, instance_type): if instance is None: return self.expr.__get__(instance_type, instance_type.__class__) return self.func.__get__(instance, instance_type) def expression(self, expr): self.expr = expr return self class hybrid_property(ModelDescriptor): def __init__(self, fget, fset=None, fdel=None, expr=None): self.fget = fget self.fset = fset self.fdel = fdel self.expr = expr or fget def __get__(self, instance, instance_type): if instance is None: return self.expr(instance_type) return self.fget(instance) def __set__(self, instance, value): if self.fset is None: raise AttributeError('Cannot set attribute.') self.fset(instance, value) def __delete__(self, instance): if self.fdel is None: raise AttributeError('Cannot delete attribute.') self.fdel(instance) def setter(self, fset): self.fset = fset return self def deleter(self, fdel): self.fdel = fdel return self def expression(self, expr): self.expr = expr return self