How to configure Python interpretor in android studio

These are steps that work:

1. Install the JetBrains Python Community Edition.
2. Click Tools -> Sync Python Requirements...
3. A notification popup appears saying you need to configure your interpreter. Click the link in that popup. That link takes you to the necessary dialog window (the one you also see in Jiya's answer.) (That the link in the notification bar takes you to a different one is probably a bug.)

when I try to write code in python is tells that "no python interpreter configured for the module"

Only a few features of the Python Community Edition plugin will work properly in Android Studio. You can still write your Python code in Android Studio if you want, but most of the IDE assistance will be unavailable.

Even if the code displays error indicators, you can still go ahead and run your app, and if any of the errors are real, the details will be displayed in the Logcat.

how can I send variables for my MainActivity to python and viceversa.

See the example code in the Chaquopy documentation and demo app.