How to fix the broken package manager?

Question

OS :debian8.

debian8@hwy:~$ sudo apt-get install python3
Reading package lists... Done
Building dependency tree   
Reading state information... Done
python3          


        

Answer 1

The first command will show you if the package is installed

~$ dpkg -l python3
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                Version        Architecture   Description
+++-===================-==============-==============-============================================
ii  python3             3.5.1-3        amd64          interactive high-level object-oriented langu

this command will show you the location of python3 program if is installed.

~$ which python3
/usr/bin/python3

re install the package you removed check I have 'ii' and you have 'ri'

apt install --reinstall python3