无法在 ubuntu 18.04 上安装 psycopg2

Question

I am trying to install python3-psycopg2 as a part of postgresql installation, but I get:

The following packages have unmet dependencies:
 python3-psycopg2 : Depends: python3 (>= 3.7~) but 3.6.7-1~18.04 is to be installed
E: Unable to correct problems, you have held broken packages.

I installed python3.8 and configured python3 link to it:

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8 1

But I still get the same error.

I have an Ubuntu 18.04 OS.

Answer 1

The Psycopg2 library is built as a wrapper around libpq and mostly written in C. It is distributed as a sdist and is built during installation. For this reason it requires some PostgreSQL binaries and headers to be present during installation.

Consider running these 2 commands:

sudo apt install python3-dev libpq-dev

The main goal of the command above is to provide all requirements for building Psycopg2 .

Then:

pip3 install psycopg2

You should have psycopg2 installed and working now.

Answer 2

While the explanation of Gitau is very good. You can simply install the psycopg2 binary instead as mentioned by Maurice:

python3 -m pip install psycopg2-binary

or just

pip install psycopg2-binary

Answer 3

Sometime psycopg2-binary is not a solution because other packages require for psycopg2 on their dependencies.

As cited above, you need to install some libs on ubuntu before install psycopg2. For me, I had to install build-essential as well.

sudo apt install python3-dev libpq-dev build-essential

and then

pip install psycopg2