[Python] How do I raise an exception when assigning to an attribute which is NOT mapped to an...

With SQLAlchemy, I'm finding that sometimes I mis-type a name of an attribute which is mapped to a column, which results in rather difficult to catch errors:

class Thing(Base):
foo = Column(String)


thing = Thing()
thing.bar = "Hello" # a typo, I actually meant thing.foo
assert thing.bar == "Hello" # works here, as thing.bar is a transient attribute created by the assignment above
session.add(thing)
session.commit() # thing.bar is not saved in the database, obviously
...
# much later
thing = session.query(Thing)...one()
assert thing.foo == "Hello" # fails
assert thing.bar == "Hello" # fails, there's no even such attribute


Is there a way to configure the mapped class so assigning to anything which is not mapped to an SQLAlchemy column would raise an exception?

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