E: Package ‘python3-pip’ has no installation candidate

오류

sudo apt-get install python3-pip
Reading package lists... Done
Building dependency tree... Done
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

해결

sudo apt-get update
# sudo apt-get upgrade
sudo apt install python3-pip