Question

I’m trying to use google.appengine.ext.deferred to run a Task. I am passing a method to the defer() method, and that method runs successfully, but upon returning, a ValueError is thrown:

  File ".../admin.py", line 73, in post
    result = deferred.defer(meeple_tasks.buildGames())
      File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/ext/deferred/deferred.py", line 198, in _curry_callable
        raise ValueError("obj must be callable")
    ValueError: obj must be callable

Here is where I call defer:

result = deferred.defer(meeple_tasks.buildGames())   

buildGames() will return True when completed.

Answer 1

You should use:

result = deferred.defer(meeple_tasks.buildGames)

If you use buildGames(), that invokes the function right then and there, passing the return value to defer(). By removing the parenthesis, you pass the function itself to defer.