[Python] Best way to get a single key from a dictionary?

Having a python dictionary and knowing it is made of just one key/value pair, what's the best way to retrieve that single/unique item?

So far I know I could use one of these two ways:

1. 
   list(mydict.keys())[0] (same as list(mydict)[0])
   
   
2. 
   next(iter(mydict.keys())) (same as next(iter(mydict)))
   

As far as I understand, list performances are worse than iter ones so the latter approach should be better, right? Which ways is best? There's something that's even better than the two way I indicated? Please let me know.

Continue reading...