Develop Reference

Not able to install pypy sandbox

As mentioned in: https://howtoinstall.co/en/python-pypy.sandbox
I tried the following code:
sudo apt-get update and then
sudo apt-get install python-pypy.sandbox
This gives me the following output:
Reading package lists... Done
Building dependency tree
Reading state information... Done
python-pypy.sandbox is already the newest version (5.1.2+dfsg-1~16.04).
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
python-pypy.sandbox : Depends: pypy-lib (= 5.1.2+dfsg-1~16.04) but it is not going to be installed
Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

In my Ubuntu18, by mistake i have deleted python folders from /usr/lib ? If i run command "sudo apt-get install --reinstall python" then not working

This is what i got after sudo apt-get install --reinstall python
$ sudo apt-get install --reinstall python
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
python : PreDepends: python-minimal (= 2.7.15~rc1-1) but it is not going to be installed
Depends: python2.7 (>= 2.7.15~rc1-1~) but it is not going to be installed
Depends: libpython-stdlib (= 2.7.15~rc1-1) but it is not going to be installed
python3-gi-cairo : Depends: python3-gi (= 3.26.1-2ubuntu1) but 3.26.1-2 is to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

meet error in running "apt-get upgrade" in ubuntu

I have tried to run "sudo apt-get upgrade" in my ubuntu system .but I get the log below. It's annoying as I searched google and no results.
sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
python-twisted-conch : Depends: python-twisted-core (>= 13.2.0-1ubuntu1.2) but 13.2.0-1ubuntu1 is installed
python-twisted-mail : Depends: python-twisted-core (>= 13.2.0-1ubuntu1.2) but 13.2.0-1ubuntu1 is installed
python-twisted-names : Depends: python-twisted-core (>= 13.2.0-1ubuntu1.2) but 13.2.0-1ubuntu1 is installed
E: Unmet dependencies. Try using -f.
My system version is as follows ,
cat /proc/version
Linux version 3.19.0-33-generic (buildd#lgw01-49) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #38~14.04.1-Ubuntu SMP Fri Nov 6 18:17:28 UTC 2015
I tried to follow the instruction of the error info but still get the same error .
sudo apt-get install -f python-twisted-conch
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
python-twisted-mail : Depends: python-twisted-core (>= 13.2.0-1ubuntu1.2) but 13.2.0-1ubuntu1 is to be installed
python-twisted-names : Depends: python-twisted-core (>= 13.2.0-1ubuntu1.2) but 13.2.0-1ubuntu1 is to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

Unmet Dependencies When installing python-pip and python-dev

As be mentioned above, I tried to install python-pip and python-dev with command:
sudo apt-get install python-pip python-dev
then I get:
sudo apt-get install python-pip python-dev
[sudo] password for tailongnguyen:
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:
python-dev : Depends: python (= 2.7.11-1) but 2.7.12-1 is to be installed
python-pip : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
Recommends: python-all-dev (>= 2.6) but it is not going to be installed
Recommends: python-setuptools but it is not going to be installed
Recommends: python-wheel but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
What I need to do now?
I tried
sudo apt-get update
sudo apt-get upgrade
but it didn't help

See this link. This resolved this issue, though I got similar issue with apache2.2-common after fixing this.
https://askubuntu.com/questions/275861/problem-installing-python-dev

Install psycopg2 on ubuntu 12.04

I am trying to install psycopg2 on the server for a Django application inside a virtualenv. I have managed to install it in the past successfully by running this command sudo apt-get -y install libpq-dev python-dev python2.7-dev before pip install psycopg2.
But now when I try to execute the first command, it shows the following error.
The following packages have unmet dependencies:
libpq-dev : Depends: libssl-dev but it is not going to be installed
Depends: libkrb5-dev but it is not going to be installed
Depends: comerr-dev but it is not going to be installed
python2.7-dev : Depends: libexpat1-dev but it is not going to be installed
Depends: libssl-dev but it is not going to be installed
Recommends: libc6-dev but it is not going to be installed or
libc-dev
E: Unable to correct problems, you have held broken packages.
How do I solve this?