shihabus/learn-fastapi

Learn FastAPI

Steps

1. Create virtual env python3 -m venv "env_name"

   1.1 Set to use venv interpreter for VSCode
   Python:Select Interpreter >> Select venv bin/python
   
   1.2 Set terminal to use venv python interpreter
   `source env_name/bin/activate`
   

2. Install FastAPI (make sure you use venv interpreter)

   pip install fastapi

   pip freeze #to see all packages installed

   pip install "uvicorn[standard]"

3. start the server uvicorn _main_script_loc_:_fastAPI_instance_name_ --reload Ex: uvicorn app.main:app --reload

4. API docs /doc or /redoc routes of the host server URL will give Swagger or Redoc API documentation automatically

5. Create modules Adding __init__.py inside a folder will make it a module

6. Database constraints NOT NULL UNIQUE

7. Packages

   • Psycopg:

     • Python PostgreSQL database adapter

       pip install psycopg2-binary

   • sqlalchemy

     • it is an ORM(Object Relation Mapper) - it let us use Python to interact with DB, and abstract away SQL - under the hood uses psycopg

       pip install SQLAlchemy==1.4.49

   • Alembic

     • If you update any tables, you have to drop current tables and replace it with the new old. While dropping you could loose the data that already exist. This is coz, sqlAlchemy don't push the table schema changes if the table is already present in the DB.

     • it can keep track of changes to DB and tables

       alembic init __dir__

       alembic revision -m "__message__"

       alembic upgrade __revision_number__

       • show current revision applied

         alembic current

       • show latest revision

         alembic heads

       • this will auto-generate the alembic version based on the current model metadata state

         alembic revision --autogenerate -m "__message__"

8. PostgresSQL

   • Composite key
     • primary keys that span more than one column
     • there might be duplicate in a column, but the row-wise combination of entries will be unique

9. PyTest

   • fixtures
     • they are like the code that run before or after each test
   • parameterize
     • used to pass different parameters to the tests

   -x # stop when a test fail
   --disable-warnings # silence warnings