user@computer:~$ sudo apt-get install idle3
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
idle3 : Depends: idle (>= 3.6.5-3) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

To solve this problem Ive tried:

sudo dpkg --configure -a
sudo apt-get clean && sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
sudo apt update
sudo apt full-upgrade
sudo apt-get autoremove
sudo aptitude install libssl-dev zliblg-dev=1:1.2.8.dfsg-1ubuntu1

after restarting my pc and reparing broken packages
sudo apt-get install -f

user@computer:~$ sudo apt install -f
[sudo] password for user: 
Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is heWaiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is heWaiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is heWaiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is heWaiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is heWaiting for cache lock: Could not get lock /var/liWaiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 6747 (synaptic)... 37s (synaptic)... 7saptic)... 6s
Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 6747 (synaptic)... 86s
^Citing for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 6747 (synaptic)... 133  

sudo apt autoclean
sudo apt clean
sudo apt-get install idle
sudo apt --fix-broken install
apt-mark showhold

also installing aptitude failed