A lot of developers want to go to 3.11 because of the speed improvements, but most distros never have the latest Python version.
Using the deadsnakes third party repo is the easiest way aside from compiling it yourself (which is safer and recommended):
Step 1 - Add the repo
apt-add-repository ppa:deadsnakes/ppa
If you get an error about requests then install it:........
Visit http://linux.softpedia.com/get/Programming/Interpreters/Android-32340.shtml
Basically copy and paste all of that below and you'll have installed and started the Android SDK before you know it.
wget http://dl.google.com/android/android-sdk_r12-linux_x86.tgz
sudo apt-get install openjdk-6-jre openjdk-6-lib openjdk-6-jre-headless
tar -xvf android-sdk_r12-linux_x86.tgz
cd android-sdk-linux_x86/tools
./android........