Ubuntu Wily (15.10) (which it looks like you might be using there, from the output) was end-of-life in 2016, and it is complaining that it can't download it's package list - Ubuntu aren't going to provide apt repositories for unsupported OSes . This OS is too old, you'll need to upgrade it. If you aren't running that old OS, then your apt sources are not configured correctly.
HI
I have the following conf :
Raspberry Pi Zero W Rev 1.1
octopi_version: 0.17.0
Octoprint 1.13.12
I did not succed to use the upgrade.py script.
Initialy I had only python 2.7
I try to install python 3.7 but I get the following message
Please upgrade to an OctoPrint version >= 1.4.0 for Python 3 compatibility
I try the following command
pip install octoprint==1.4.0
It seem's to work (no warning or error)
But with a :
sudo service octoprint start
My octoprint version is still 1.13.12
How can I upograde without reflasing the SD card?
run this after running the command source ~/oprint/bin/activate
Wonderfull you are the boss 
Thanks, now just have to pass to python 3...