Ok, so technically you can make an accessible GUI with Pygame if you implement incredibly difficult to implement accessibility API stuff that's different for every platform and for which no one has a cross-platform solution, but this will take you months of effort at minimum--I mean actual months, not I do this in the evening months--and no one else has already done it. So for all practical purposes the answer is you can't.
If you are blind, and you don't care about graphics, you can do everything a game needs in WX no problem. The event handling for keyboard and whatever is all there. If you do care about graphics, you can do almost everything you need in wx, then get an OpenGL context out of it. I don't know what the next step of that would be in Python; in C/C++ you can take that OpenGL context and give it to the OpenGL API, and in fact in those languages that's the normal way of getting one. It's possible that Pyglet can do your rendering in that case because it's specifically written to interface with OpenGL and the other game-type stuff is sort of incidental, but you'd still need to actually have WX handling the GUI elements. E.g. you'd put your graphics in a panel and use WX styling to overlay controls, or put the controls to the side, or something like that.
There's always plan C of giving all your controls keyboard support and then making them self-voicing, which does work, but for that your problem is that edit boxes are a difficult problem because you're reimplementing your own screen reader, so you'd have to e.g. use something like libfiledialogs or whatever it's called to pop normal ones up when the user wants to edit. Also, I entirely hate how the world we live in is the "just hack it, this might be your best option because no one has cared enough to make this easy" one, but here we are.
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