Python 有没有办法将sqlalchemy orm实例转储到json？

我用python编写这个函数是为了将对象转储到json。有没有更好、更经过测试的方法来使用这个库呢

def model_jsonify(self,instance):
    from sqlalchemy.orm import class_mapper , ColumnProperty
    attrs = [prop.key for prop in class_mapper(instance.__class__).iterate_properties if isinstance(prop, ColumnProperty)]

    r = dict()

    for attr in attrs :
        c = getattr(instance,attr)
        assert not c is None
        r[attr] = c

    return r

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为了完成这个问题，我编写了以下代码。您可以查询简单的ORM对象或列表（查询联接时的结果）。但您不能序列化单个字段（如仅查询带有某些字段的联接）

这是我用两个查询编写的一个小测试：

purchaseorder = mi.session.query(PurchaseOrder).first()
assert purchaseorder != None

j = mi.model_jsonify (purchaseorder)
assert not j is None
assert isinstance(j,dict)

assert j['purchaseorder']['name'] == 'january'

bompurchaseorderlines = mi.session.query(BoMPurchaseOrderLine,SupplierLine).join(SupplierLine).all()
assert not bompurchaseorderlines is None

for purchaseorder in bompurchaseorderlines :
    j = mi.model_jsonify (purchaseorder)

---

我认为你的功能已经很好了。到目前为止有什么缺点吗？这似乎在[如何将SQLalchemy创建为JSON][1][1]中有所介绍：是的，它几乎是同一个函数，我以前没有找到过它

purchaseorder = mi.session.query(PurchaseOrder).first()
assert purchaseorder != None

j = mi.model_jsonify (purchaseorder)
assert not j is None
assert isinstance(j,dict)

assert j['purchaseorder']['name'] == 'january'

bompurchaseorderlines = mi.session.query(BoMPurchaseOrderLine,SupplierLine).join(SupplierLine).all()
assert not bompurchaseorderlines is None

for purchaseorder in bompurchaseorderlines :
    j = mi.model_jsonify (purchaseorder)