Electrum console commands?
x=10

for thing in range(0,x): wallet.create_new_address()

listaddresses(True,False,False,False,True)


A guide about console commands is here. Thanks to @RichApodaca for pointing that out.

Another resource is the code itself. For example you can see the function declaration for listaddresses here which tells you what all those boolean args are for. In the above case it only outputs unused addresses in the external (receive) chain.