I believe int(s, base) needs an inverse function to allow string representation with different bases. An example use case is 'hashing' a counter like video ID's on youtube, you could use a regular int internally and publish a shorter base-62 id 
for links.

This subject was discussed 2.5 years ago:

I opened a feature request ticket:

Some of the questions that remain:
1. Whether this should be a method for int or a regular function in a standard library module like math.
2. What should the method/function be called? (base_convert, radix, etc)

What do you guys think?