database.py:
from sqlalchemy import create_engine from sqlalchemy.orm import sessionmaker, Session from sqlalchemy.ext.declarative import declarative_baseDATABASE_URL = 'postgresql://postgres:postgres@localhost/TodoAppDB'engine = create_engine(DATABASE_URL)SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine) # Now we need to create a SessionLocal and each instance of the SessionLocal will have a database session. # The class itself is not a database session yet. We will add that later on. # But right now we just need to be able to create an instance of SessionLocal that will be able to become an actual database in the future. Base = declarative_base() # create an object of our database which will then be able to interact with the tables that we create in the future.def get_db():db = SessionLocal()try:yield dbfinally:db.close()
(fastapi-venv) frank@ZZHPC:~/zproject/TodoApp$ uvicorn main:app --reload
......
ModuleNotFoundError: No module named 'psycopg2'
(fastapi-venv) frank@ZZHPC:~/zproject/TodoApp$ dpkg -l libpq-dev dpkg-query: no packages found matching libpq-dev (fastapi-venv) frank@ZZHPC:~/zproject/TodoApp$ sudo apt install libpq-dev [sudo] password for frank: Reading package lists... Done Building dependency tree... Done Reading state information... Done The following package was automatically installed and is no longer required:libwayland-server0 Use 'sudo apt autoremove' to remove it. The following additional packages will be installed:libpq5 Suggested packages:postgresql-doc-16 The following NEW packages will be installed:libpq-dev libpq5 0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. Need to get 298 kB of archives. After this operation, 1048 kB of additional disk space will be used. Do you want to continue? [Y/n] Y Get:1 http://archive.ubuntu.com/ubuntu noble-updates/main amd64 libpq5 amd64 16.13-0ubuntu0.24.04.1 [146 kB] Get:2 http://archive.ubuntu.com/ubuntu noble-updates/main amd64 libpq-dev amd64 16.13-0ubuntu0.24.04.1 [152 kB] Fetched 298 kB in 3s (87.6 kB/s) Selecting previously unselected package libpq5:amd64. (Reading database ... 59400 files and directories currently installed.) Preparing to unpack .../libpq5_16.13-0ubuntu0.24.04.1_amd64.deb ... Unpacking libpq5:amd64 (16.13-0ubuntu0.24.04.1) ... Selecting previously unselected package libpq-dev. Preparing to unpack .../libpq-dev_16.13-0ubuntu0.24.04.1_amd64.deb ... Unpacking libpq-dev (16.13-0ubuntu0.24.04.1) ... Setting up libpq5:amd64 (16.13-0ubuntu0.24.04.1) ... Setting up libpq-dev (16.13-0ubuntu0.24.04.1) ... Processing triggers for libc-bin (2.39-0ubuntu8.7) ... Processing triggers for man-db (2.12.0-4build2) ... (fastapi-venv) frank@ZZHPC:~/zproject/TodoApp$ pip install psycopg2 Collecting psycopg2Downloading psycopg2-2.9.11.tar.gz (379 kB)Installing build dependencies ... doneGetting requirements to build wheel ... donePreparing metadata (pyproject.toml) ... done Building wheels for collected packages: psycopg2Building wheel for psycopg2 (pyproject.toml) ... doneCreated wheel for psycopg2: filename=psycopg2-2.9.11-cp313-cp313-linux_x86_64.whl size=550339 sha256=e8e6b2953ba0dcc8f27764b841935b401e18dd4c20a8376da95efa09f5f625daStored in directory: /home/frank/.cache/pip/wheels/63/ed/1a/7f7f58e98cbe6623951e4308d81a93c8087d1ac9804513a056 Successfully built psycopg2 Installing collected packages: psycopg2 Successfully installed psycopg2-2.9.11