python: union keys from multiple dictionary?

Question

I have 5 dictionaries and I want a union of their keys.

alldict =  [dict1, dict2, dict3, dict4, dict5]

I tried

allkey = reduce(         


        

Answer 1

I think @chuck already answered the question why it doesn't work, but a simpler way to do this would be to remember that the union method can take multiple arguments:

allkey = set().union(*alldict)

does what you want without any loops or lambdas.