Would it ever be possible to convert Python to Minecraft command blocks?

It really depends on what you mean by that. If you mean doing things inside the game like automating tasks using Python, it's not completely out of the question. The mod OpenComputers adds computer blocks and items which allow you to do something like that using Lua.

If you mean writing Python scripts that interact with the game from the outside, then yes; in fact, the Rasperry Pi edition of the game is made to do just that. As stated in the comments to your question by randomuser922, there's even a mod that simulates these features.

If you mean translating Python code to Minecraft commands... not really. But there are a few programming languages made to facilitate writing Minecraft commands, such as Command Block Language or MPL. These compile into command blocks which you can then import into a world.