How to install python3-pip on ubuntu 20.04

Question

I installed Ubuntu 20.04 on a PC. I then tried to get started and install pip for python3. However nothing seemed to work. This is what I have tried so far:

sudo apt install python3-pip

This is the error I get:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package python3-pip is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'python3-pip' has no installation candidate

I have tried the solution proposed by Carlos Sanchez JR.: How to install Python package installer PIP on Ubuntu 20.04 Linux

After following the advice given in the link above I got this error when doing sudo apt update :

Ign:1 cdrom://Ubuntu 20.04 LTS _Focal Fossa_ - Release amd64 (20200423) focal InRelease
Hit:2 cdrom://Ubuntu 20.04 LTS _Focal Fossa_ - Release amd64 (20200423) focal Release
Hit:4 http://security.ubuntu.com/ubuntu focal-security InRelease              
Hit:6 http://archive.ubuntu.com/ubuntu focal InRelease                        
Get:5 http://kali.download/kali kali-rolling InRelease [30.5 kB]
Hit:7 http://archive.ubuntu.com/ubuntu focal-updates InRelease
Err:5 http://kali.download/kali kali-rolling InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ED444FF07D8D0BF6
Get:8 http://kali.cs.nctu.edu.tw/kali kali-rolling InRelease [30.5 kB]
Err:8 http://kali.cs.nctu.edu.tw/kali kali-rolling InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ED444FF07D8D0BF6
Reading package lists... Done
W: GPG error: http://kali.download/kali kali-rolling InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ED444FF07D8D0BF6
E: The repository 'http://http.kali.org/kali kali-rolling InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://kali.cs.nctu.edu.tw/kali kali-rolling InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ED444FF07D8D0BF6
E: The repository 'http://kali.cs.nctu.edu.tw/kali kali-rolling InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Trying sudo apt install python3-pip at this point just gives me the same E: Package 'python3-pip' has no installation candidate error as before. This is equally true when trying sudo apt-get install python3-pip.

I have found no other solutions to this problem.

Answer 1

Try this command

sudo apt-get install python3-pip

Note: If you have a fresh install, you need to do this first before trying the above command.

sudo apt-get update