pgpasslib is a library for retrieving passwords from a PostgreSQL password file, either from a location specified in the PGPASSFILE environment variable or in the .pgpass file in the current user's home directory.

pgpasslib may be installed via the Python package index with the tool of your choice. I prefer pip:

pip install pgpasslib

https://pgpasslib.readthedocs.org

There are no requirements outside of the Python standard library.

The following example will attempt to get the password for PostgreSQL running on localhost:5432 to the postgres database as the postgres user.

import pgpasslib

password = pgpasslib.getpass('localhost', 5432, 'postgres', 'postgres')
if not password:
    raise ValueError('Did not find a password in the .pgpass file')

Available at https://pgpasslib.readthedocs.org