You are not getting the idea. Dictionaries are used for speed, yes. But for speed of what? The speed of finding a value by unique key, the computational time complexity
of this search is O(1), that's is, it asymptotically
does not depend on the number of items.
If you simply read the lines of a file, you can use them as vales, as keys, but not as key-value pairs used in dictionary. And if your keys and values are the same, it gives you nothing, because if you know they are the same and have a key, why looking for a value? (However, it will guarantee key uniqueness, but for this purpose, you should use the class
This way, your question simply makes no sense
. If you explain what are you going to do with a dictionary (first of all, to yourself), I would gladly help.