I want to install kivy (link here) to use for a project, however, when trying to use pip to install the packages it is dependent upon, I get the following error:
Could not find a version that satisfies the requirement kivy.deps.sdl2 (from versions: )
No matching distribution found for kivy.deps.sdl2
Further reading on kivy's website revealed that these libraries do not support Python 3.5 on windows 10 because of some kind of graphical bug. The website says you need python 3.4 in order to be able to install it.
Which brings the question: How do I install python 3.4 when I already have python 3.5?
Uninstall Python 3.5 by going to control panel, uninstall a program, and then look for Python 3.5, click on it and press uninstall. After that download Python 3.4. I don't know any other ways but I think that should work.
If you have an Anaconda installation you can just type:
conda install python=3.4
And it installs 3.4, to re-install 3.5, it's
conda install python=3.5
It works in under a minute.
I was able to install Python 3.4 in a separate directory and then just change the default interpreter in PyCharm to use the new directory containing 3.4 instead.
来源：https://stackoverflow.com/questions/36924703/how-to-downgrade-to-python-3-4-from-3-5