update

README.md

@@ -13,4 +13,17 @@ Download the Lite Image from here: https://www.raspberrypi.org/software/operatin
 - Inserd SD-card in your raspi and power it up. Wait afew minutes to let it boot up.
 - you can get the IP of your raspi by looking at your dhcp-server or your wlan-router
 - login via ssh on your raspberry pi with the user pi and raspberry as password
-- open up "sudo raspi-config" and change your pi password!
+- open up `sudo raspi-config` and change your pi password!
+- expand filesystem to get the most of your SD-card space
+
+# prepair anything else
+- create a ssh key with `ssh-keygen` for user pi
+- go to admcenter and `ssh-copy-id pi@<your-pi-ip>` and login with your new pi password
+- initiate the new system with ansible `ansible-playbook -i <your-pi-ip>, -u pi /etc/ansible/playbooks/init.yml`
+
+# python3 installation
+- install python3 with `sudo apt install python3 python3-dev`
+- generate alternatives:
+    - `update-alternatives --install /usr/bin/python python /usr/bin/python3.7 2 # on debian buster default python3 is 3.7`
+    - `update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1 # old python version`
+