Promises using closures

gistfile1.py

def DoABigThing(aListOfNumbers, callWhenSucceededF, callWhenFailedF):
  def DoTheThing(resolve, initialValue):
    theSum = sum(aListOfNumbers) + initialValue
    theSum += # also get some stuff from a webservice or datastore or something else slow?
    resolve(theSum)

  def DoneTheThing(result):
    try:
      callWhenSucceededF(result.value)
    except Exception, ex:
      callWhenFailedF(ex)
  
  PromiseSpace().when(DoTheThing, 47).then(DoneTheThing)