How can I pass my locals and access the variables directly from another function?

Let's say I have this :

def a(dict):
  locals().update(dict)
  print size

def b():
  size = 20
  f(locals())

What do I have to do to access the size variable directly from the a function? I know of :

size = dict["size"]

but I think there should be a more direct way. I tried using locals().update(dict) but it didn't work. Is there a betteer way ?