Question

如果属性不等于None，我想更新SQLAlchemy DB中列的值。

此方法有效，但似乎不遵循DRY主体

def editObject(object_id, name, picture, metaTitle, 
    metaKeywords, metaDescription):

    object = session.query(Object).filter_by(id = object_id).one()

    if name:
        object.name = name
    if picture:
        object.picture = picture
    if metaTitle:
        object.metaTitle = metaTitle
    if metaKeywords:
        object.metaKeywords = metaKeywords
    if metaDescription:
        object.metaDescription = metaDescription

    session.add(object)
    session.commit()

谢谢

Answer 1

您可以使用关键字参数和setattr()

def editObject(object_id, **kwargs):

    object = session.query(Object).filter_by(id = object_id).one()

    for attr, value in kwargs.iteritems():
        if value:
            setattr(object, attr, value)

    session.add(object)
    session.commit()

Answer 2

使用关键字参数setattr和列表理解：

def editObject(object_id, **kwargs):

    object = session.query(Object).filter_by(id = object_id).one()

    [setattr(object, key, value) for key, value in kwargs.items()]

    session.add(object)
    session.commit()

然后当您调用该函数时，例如：

object_id = 1
attributes_to_update = {"name": "smith", "metaKeywords": "handsome_devil"}
editObject(object_id, **attributes_to_update)

在该示例中，只会更新name和metaKeywords。

Python：如果不是更新，则更新属性值

2 个答案: