Appending sqlalchemy queries filters dynamically?

Question

Is it currently possible to breakdown sqlalchemy queries into parts and chain them together in code. For example

The query below

results = Session.query(foo).filter(conditionA).filter(conditionB).filter(conditionC).all()

Broken down into

MyConditions = None
if (...)
  MyCondition += filter(conditionA)

if (...)
  MyCondition += filter(conditionB)
if (...)
  MyCondition += filter(conditionC)

Session.query(foo) + MyCondition + all()