Python: compare keys of 2 dictionaries and update the value of one
===

I have 2 dictionaries with the same keys:

    d={123:'bla', 456: blabla}
    e={123:'bla', 456:''}

Dictionary e has some empty values and if this is the case and the IDs are the same I'd like to replace the empty value with the value from d.

I am looking for something like this:
    
    if d.keys()==e.keys():
	    e.values==d.values()
	print e

However, I couldn't find anything in the Python documentation that compares single keys and updates the values. 

Can someone help or point me at something?

Thanks :)