OpenGL hardware acceleration | Allows for easy debugging: It has a built-in Python interpreter that allows for easy debugging. | Greater performance than high level APIs: Cocos2d-x is C++ based engine and it has CPU advantages for most platforms because of that. It uses polygonal mesh methods for sprite rendering for using GPU advantages. (You also use quad methods for benefit CPU). | Good documentation: Documentation includes a programming guide, API reference, video tutorials and massive reference test code project showing all functions and giving working code to the user. · | Great script language support: It supports Lua and Javascript with full feature support. · Especially with Cocos2d-JS you can develop games cross web and native, and the native solution have great performance with JS Bindings, much better than hybrid solution. | A proven engine for mobile development: 25% of iPhone games are made using Cocos2d-x (A Cocos2d mobile variant.) · This means you will not be alone in development, and will have access to a large community. You'll know you are developing for an engine that works. | Supports 3D models with skeleton animation: A new feature since Cocos2d-x v3.1 is support for 3D models (in your 2D game), not only this but support for skeleton animations is included too! This awesome feature allows for impressive characters in your game along with easier, more fluid and realistic animations. | Poor documentation: Most existing documentation is out of date. API documentation sometimes exists, though is usually just a one-liner and more often than not is completely absent. New features and significant system rewrites often make it to a major release without a single line of documentation accompanying them. Cocos2d-x family is developed by Chinese mostly, so market outside of China is not their main priority. Some tools (like Cocos Studio) have China-specific services and markets. | Can seem very complex for a novice developer: There isn't much documentation or tutorials. | Modest functionality: Almost all free alternatives are more convenient, faster, and more functional. | Poor support and non-existent community: Up until 2013, this was one of the best engines around. However, since then it was bought by a Chinese company and began stagnating - it's virtually in a slow death. Most developers abandoned Cocos in favor of more modern solutions leaving the community weak and the forums with little or no traffic. Although the Cocos2d-x Forum seems to have a decent community going. | Messy documentation: Most existing documentation is out of date. API documentation sometimes exists, though is usually just a one-liner and more often than not is completely absent. New features and significant system rewrites often make it to a major release without a single line of documentation accompanying them. | As the first member in cocos2d family, cocos2d python shares the majority of the concepts with other cocos2d family members, like cocos2d-x, eg: scene, sprite, action... so learning game developing from cocos2d python will be a good start, it will make you learn other cocos2d variants easily.

Pygame is just a wrapper for SDL, so technically a lot of games have been made using it, most of the work is done C-side anyways. It's a little slow, though if you are doing a 2D game, it should be sufficient. Frets-on-Fire was written in pure python with PyGame, and FoFiX was written in python with C extensions, and those games are both pretty great, altough on slower computers FoFiX can have trouble running 4 player.

Pyglet is also pretty nice, though I've only used it for emulator development, drawing single layers, so I don't know how well it actually works for game development. I've found that it's much easier to use direct OpenGL with Pyglet than it is with SDL/PyGame, so if you are doing a 3D game, it's probably better than using SDL. Also, since it's written in python, it's very easy to extend classes to change how a function is handled. For instance, I was trying to load data into an openGL texture through the pyglet Texture class, but the class couldn't load the data in a format I wanted, so I extended that class and changed the function that got the texture type (comes from a string) to include the texture I wanted, quick and painless.

One library I don't see mentioned enough is SFML. The 2.0 API (currently in beta) is pretty stellar and simple to use, and, if I remember correctly, runs a little faster than SDL. It is also more "object oriented" than SDL, which is really nice if you are working in an OO language like Python. It has some nice Python bindings written by Bastien Leonard in Cython that are pretty easy to use (or you can use the old C bindings if you don't want to use the most up to date version). I used this a while back and it was quite an enjoyable experience.

The reason why there aren't a lot of shipped games using Python is pretty simple: You can't close Python source. Even if you "compile" python into an executable using Py2Exe or something, it really just packs up the interpreter and python source into an exe file, and the source can be got just by opening up the exe in a hex editor.

While I'm a supporter of the "write it in Python, write time critical parts in C", if you feel python is going to be too slow, I would probably suggest C or, preferably, C++ as the way to go, simply because you don't get that much of a usability advantage for writing in Java, and the C languages can be quite a bit faster running than Java, and Lua will just take away some of the usability of Python without giving you any noticeable performance enhancement. SFML and SDL can both be used straight from C(++).

Advice if you do decide to use python: Use it as it is supposed to be used, as a scripting language. Do not try to bit twiddle or load images in pure python, either use the interfaces available in the library you choose (they all have very good interfaces for those kinds of things) or write an extension module to do that for you. Use python for logic control and fetching data from your libraries. If you follow that simple rule, you really shouldn't run into any performance issues.

rabbyt. Maybe not exactly what you're looking for, but it's at least a step up from raw pygame. 2d on a 3d canvas, so it's hardware accelerated.

I can't answer much in terms of actual python libraries, but if you'd like a full game engine with a language rather close to python in its syntax, check out godot:

https://godotengine.org/