ImportError "no pq wrapper available" when importing psycopg3

Question

I installed pyscopg3 on my venv using pip install psycopg[binary] as per the documentation but I still get an import error:

Exception has occurred: ImportError
no pq wrapper available.
Attempts made:
- couldn't import psycopg 'c' implementation: No module named 'psycopg_c'
- couldn't import psycopg 'binary' implementation: DLL load failed while importing pq: The specified module could not be found.
- couldn't import psycopg 'python' implementation: libpq library not found

I'm running a Windows 10 machine. How can I solve this error?

Answer 1

You need to install the command line tools on PostgreSQL on your Windows machine. Download the full server installer here: https://www.enterprisedb.com/downloads/postgres-postgresql-downloads

You don't need to install the full server package, only command line tools in the installer options will be necessary:

After the installation, you need to add the PostgreSQL bin folder in your PATH environnement variable:

hit +R at the same time to get command prompt. Then type sysdm.cpl, go to advanced and select "Environment Variables", in PATH add the path to : C:\Program Files\PostgreSQL\13\bin\ folder (or whatever folder you choose to install the PostreSQL commande line tools).

IMPORTANT: do not forget to close and restart your dev environnement (ie: VSCode, PyCharm, ...) to take the new environnement variable into account.

Note : This answer is related to Windows machine. For Linux the installation of a at least one postgresql-client-<version> package will be enough.

related to: https://stackoverflow.com/a/60369228/5341247

Answer 2

I followed the psycopg installation steps from https://pypi.org/project/psycopg/

pip install --upgrade pip           # to upgrade pip

pip install "psycopg[binary,pool]"  # to install package and dependencies

it worked for me