Could not find a version that satisfies the requirement tensorflow
(as of Jan 1st, 2021)
Any over version 3.9.x there is no support for TensorFlow 2. If you are installing packages via pip with 3.9, you simply get a "package doesn't exist" message. After reverting to the latest 3.8.x. Thought I would drop this here, I will update when 3.9.x is working with Tensorflow 2.x
I installed the latest version of Python (3.6.4 64-bit) and the latest version of PyCharm (2017.3.3 64-bit). Then I installed some modules in PyCharm (Numpy, Pandas, etc), but when I tried installing Tensorflow it didn't install, and I got the error message: 

Could not find a version that satisfies the requirement TensorFlow (from versions: )
      No matching distribution found for TensorFlow.

Then I tried installing TensorFlow from the command prompt and I got the same error message.
I did however successfully install tflearn. 
I also installed Python 2.7, but I got the same error message again. I googled the error and tried some of the things which were suggested to other people, but nothing worked (this included installing Flask). 
How can I install Tensorflow? Thanks.