please try N0berts answer first
I would recommend reinstalling possibly problematic packages at a low level:
export PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"
cd ~/Downloads
apt-get download python3-minimal
sudo -E dpkg -i --force-all ./python3-minimal*.deb
sudo -E dpkg --configure -a
sudo -E apt-get install -f
sudo -E apt-get install --reinstall python3-minimal
sudo -E apt-get install --reinstall $(dpkg -l | grep ^ii | grep python | awk '{print $2}')
sudo -E dpkg --configure -a
sudo -E apt-get install -f
sudo -E apt-get install aptitude
sudo -E aptitude safe-upgrade
sudo -E aptitude dist-upgrade
Try to fix each package separately:
mkdir ~/Downloads/debs
cd ~/Downloads/debs
apt-get download devhelp dput gdebi-core python3 python3-psutil apport python3-tz python3-apport python3-cupshelpers python3-monotonic python3-requests-unixsocket python3-six python3-simplejson python3-cups python3-oauthlib python3-chardet python3-configobj python3-secretstorage system-config-printer python3-certifi python3-pexpect python3-cryptography python3-wadllib python3-gi python3-requests python3-ldb python3-idna python3-fasteners python3-urllib3 gnome-shell ubuntu-session ibus gdm3 python3-defer duplicity python3-keyring python3-httplib2 language-selector-common python3-paramiko lsb-release python3-protobuf python3-future python3-rfc3339 python3-macaroonbakery python3-aptdaemon.gtk3widgets python3-ibus-1.0 python3-lazr.restfulclient python3-gi-cairo python3-lib2to3 terminator python3-nacl python3-systemd python3-cffi-backend
sudo dpkg -i --force-all ./devhelp*.deb
sudo dpkg -i --force-all ./dput*.deb
sudo dpkg -i --force-all ./gdebi-core*.deb
sudo dpkg -i --force-all ./python3*.deb
sudo dpkg -i --force-all ./python3-psutil*.deb
sudo dpkg -i --force-all ./apport*.deb
sudo dpkg -i --force-all ./python3-tz*.deb
sudo dpkg -i --force-all ./python3-apport*.deb
sudo dpkg -i --force-all ./python3-cupshelpers*.deb
sudo dpkg -i --force-all ./python3-monotonic*.deb
sudo dpkg -i --force-all ./python3-requests-unixsocket*.deb
sudo dpkg -i --force-all ./python3-six*.deb
sudo dpkg -i --force-all ./python3-simplejson*.deb
sudo dpkg -i --force-all ./python3-cups*.deb
sudo dpkg -i --force-all ./python3-oauthlib*.deb
sudo dpkg -i --force-all ./python3-chardet*.deb
sudo dpkg -i --force-all ./python3-configobj*.deb
sudo dpkg -i --force-all ./python3-secretstorage*.deb
sudo dpkg -i --force-all ./system-config-printer*.deb
sudo dpkg -i --force-all ./python3-certifi*.deb
sudo dpkg -i --force-all ./python3-pexpect*.deb
sudo dpkg -i --force-all ./python3-cryptography*.deb
sudo dpkg -i --force-all ./python3-wadllib*.deb
sudo dpkg -i --force-all ./python3-gi*.deb
sudo dpkg -i --force-all ./python3-requests*.deb
sudo dpkg -i --force-all ./python3-ldb*.deb
sudo dpkg -i --force-all ./python3-idna*.deb
sudo dpkg -i --force-all ./python3-fasteners*.deb
sudo dpkg -i --force-all ./python3-urllib3*.deb
sudo dpkg -i --force-all ./gnome-shell*.deb
sudo dpkg -i --force-all ./ubuntu-session*.deb
sudo dpkg -i --force-all ./ibus*.deb
sudo dpkg -i --force-all ./gdm3*.deb
sudo dpkg -i --force-all ./python3-defer*.deb
sudo dpkg -i --force-all ./duplicity*.deb
sudo dpkg -i --force-all ./python3-keyring*.deb
sudo dpkg -i --force-all ./python3-httplib2*.deb
sudo dpkg -i --force-all ./language-selector-common*.deb
sudo dpkg -i --force-all ./python3-paramiko*.deb
sudo dpkg -i --force-all ./lsb-release*.deb
sudo dpkg -i --force-all ./python3-protobuf*.deb
sudo dpkg -i --force-all ./python3-future*.deb
sudo dpkg -i --force-all ./python3-rfc3339*.deb
sudo dpkg -i --force-all ./python3-macaroonbakery*.deb
sudo dpkg -i --force-all ./python3-aptdaemon.gtk3widgets*.deb
sudo dpkg -i --force-all ./python3-ibus-1.0*.deb
sudo dpkg -i --force-all ./python3-lazr.restfulclient*.deb
sudo dpkg -i --force-all ./python3-gi-cairo*.deb
sudo dpkg -i --force-all ./python3-lib2to3*.deb
sudo dpkg -i --force-all ./terminator*.deb
sudo dpkg -i --force-all ./python3-nacl*.deb
sudo dpkg -i --force-all ./python3-systemd*.deb
sudo dpkg -i --force-all ./python3-cffi-backend
sudo apt-get install --reinstall devhelp dput gdebi-core python3 python3-psutil apport python3-tz python3-apport python3-cupshelpers python3-monotonic python3-requests-unixsocket python3-six python3-simplejson python3-cups python3-oauthlib python3-chardet python3-configobj python3-secretstorage system-config-printer python3-certifi python3-pexpect python3-cryptography python3-wadllib python3-gi python3-requests python3-ldb python3-idna python3-fasteners python3-urllib3 gnome-shell ubuntu-session ibus gdm3 python3-defer duplicity python3-keyring python3-httplib2 language-selector-common python3-paramiko lsb-release python3-protobuf python3-future python3-rfc3339 python3-macaroonbakery python3-aptdaemon.gtk3widgets python3-ibus-1.0 python3-lazr.restfulclient python3-gi-cairo python3-lib2to3 terminator python3-nacl python3-systemd python3-cffi-backend
and then repeat the above commands from a smaller code block.
If N0berts answer didn't work then I am sorry, You need to go on to dangerous commands or complete reinstall
Before running the below commands please do the following(it is optional but let us not take a risk) -
Please don't break your system by doing something you shouldn't have done, If you don't understand anything please ask, I am pretty sure that most of the commands will just go above your head, So feel free to ask anything.
First of all start by running
sudo apt --fix-broken install
After running the above command try installing aptitude once again by
sudo apt -f install aptitude
Let's see if this works or not
If this didn't work then try running this
sudo rm -rf /var/cache/apt/archives/*.deb
After this try installing aptitude once again
If the error is still there then there is no luck for friendly solutions, but you need to forcefully remove all the problem packages
How to do that
See the error message
Errors were encountered while processing:
python3
python3-psutil
apport
python3-tz
python3-apport
python3-cupshelpers
python3-monotonic
python3-requests-unixsocket
python3-six
python3-simplejson
python3-cups
python3-oauthlib
python3-chardet
python3-configobj
python3-secretstorage
system-config-printer
python3-certifi
python3-pexpect
python3-cryptography
python3-wadllib
python3-gi
python3-requests
python3-ldb
python3-idna
python3-fasteners
python3-urllib3
gnome-shell
ubuntu-session
ibus
gdm3
python3-defer
duplicity
python3-keyring
python3-httplib2
language-selector-common
python3-paramiko
lsb-release
python3-protobuf
python3-future
python3-rfc3339
python3-macaroonbakery
python3-aptdaemon.gtk3widgets
python3-ibus-1.0
python3-lazr.restfulclient
python3-gi-cairo
python3-lib2to3
terminator
python3-nacl
python3-systemd
python3-cffi-backend
Processing was halted because there were too many errors.
So to fix you need to manually remove them from doing database
how
Do this all in grub recovery mode by pressing the shift key before the boot logo appears and the advanced option for ubuntu > Recovery mode > Drop to a root shell // OR Open a TTY first to run the below commands by pressing ctrl + alt + f5, log in there with your (sudo)username and password
Go to /var/lib/dpkg/info
cd /var/lib/dpkg/info/
Now as we saw the error above we need to delete problem packages
See this line
errors were encountered during processing
It means after this line everything that came is just a package name
So the first package is "python3"
sudo mv python3* $HOME
### WARNING DON'T CLOSE THE SHELL DON'T DO ANYTHING AFTER THAT
Hey, listen here we are not removing the files but just moving them to some other location, So, in case anything bad happens we can still fix it as we have backup
Then test again
sudo apt -f install aptitude
Again see the error message (most of the errors were gone after this)
Then do the same with all the error packages again (sudo mv error-package* $HOME)
So after doing the above all, You will see you can install and use apt packages
Now fix everything copy/paste this line (if you are in a try then you need to manually type this)
for package in $(apt-get upgrade 2>&1 | grep "warning: files list file for package '" | grep -Po "[^'\n ]+'" | grep -Po "[^']+"); do apt-get install --reinstall "$package"; done
if this didn't return anything run sudo apt install python3-all, you will still get an error message saying that files for package x are missing, don't bother that error
At last no matter, what happens, You need to run these commands.
MAKE SURE TO RUN-
sudo apt install python3-all
sudo apt install aptitude
sudo aptitude -f upgrade
sudo aptitude -f install --reinstall ubuntu-session
sudo reboot
Now more it less your problem should be solved
