Copy an entity in Google App Engine datastore in Python without knowing property names at 'compile' time

Question

In a Python Google App Engine app I\'m writing, I have an entity stored in the datastore that I need to retrieve, make an exact copy of it (with the exception of the key), a

Answer 1

A variation inspired in Nick's answer which handles the case in which your entity has a (repeated) StructuredProperty, where the StructuredProperty itself has ComputedProperties. It can probably be written more tersely with dict comprehension somehow, but here is the longer version that worked for me:

def removeComputedProps(klass,oldDicc):
  dicc = {}
  for key,propertType in klass._properties.iteritems():
      if type(propertType) is ndb.StructuredProperty:
          purged = []
          for item in oldDicc[key]:
              purged.append(removeComputedProps(propertType._modelclass,item))
          dicc[key]=purged
      else:
          if type(propertType) is not ndb.ComputedProperty:
              dicc[key] = oldDicc[key]
  return dicc

def cloneEntity(entity):
  oldDicc = entity.to_dict() 
  klass = entity.__class__
  dicc = removeComputedProps(klass,oldDicc)
  return klass(**dicc)