More comments in code

app/common.py

@@ -2,12 +2,11 @@ import os
 import secrets
 from pathlib import Path
 
-from dotenv import load_dotenv
-
 from fastapi.templating import Jinja2Templates
 from pydantic import BaseSettings
 
 
+# Directories
 file_dir = Path(__file__).parent
 templates_dir = str(
     file_dir.parent / 'templates'
@@ -17,6 +16,7 @@ static_dir = str(
 )
 
 
+# Main configuration
 class Settings(BaseSettings):
     debug: bool = False
     session_key: str = secrets.token_hex(32)
@@ -25,6 +25,7 @@ class Settings(BaseSettings):
 settings = Settings()
 
 
+# Jinja templates handler
 templates = Jinja2Templates(
     directory=templates_dir,
 )

app/main.py

@@ -22,16 +22,24 @@ paths: List[Type[Paths]] = [
 ]
 
 
+# Initialize SQL database
 db.Base.metadata.create_all(bind=db.engine)
+
+# Create app
 app = FastAPI()
+
+# Mount static files server
 app.mount(
     '/static',
     StaticFiles(directory=common.static_dir),
     name='static',
 )
+
+# Add paths
 for p in paths:
     p(app).add_paths()
 
+# Add WTForms CSRF protection middlewares
 app.add_middleware(
     SessionMiddleware,
     secret_key=common.settings.session_key,

app/paths/errors.py

@@ -20,6 +20,7 @@ class ErrorsPaths(Paths):
 
     def add_paths(self) -> None:
 
+        # For each HTTP code specified above
         for code in codes:
             self.add_handler(code)
     
@@ -31,14 +32,19 @@ class ErrorsPaths(Paths):
             code (int): HTTP error code
         """
 
+        # Jinja template file name
+        # e.g. 404.html for 404 code
         file = Path(common.templates_dir) / f'{code}.html'
 
+        # Exit from the function
+        # if the template does not exist
         if not file.exists():
             return
 
         @self.app.exception_handler(code)
         async def handler(req: Request, exc: HTTPException) -> Response:
 
+            # Respond with the template
             return respond.with_tmpl(
                 f'{code}.html',
                 code=code,

app/sql/crud.py

@@ -6,6 +6,7 @@ from . import models
 from . import schemas
 
 
+# SELECT * from users LIMIT 1
 def get_user(
         db: Session,
         user_id: int) -> Optional[models.User]:
@@ -16,6 +17,7 @@ def get_user(
         .first()
 
 
+# SELECT * from users
 def get_users(
         db: Session,
         skip: int = 0,
@@ -28,6 +30,7 @@ def get_users(
         .all()
 
 
+# INSERT INTO users
 def create_user(
         db: Session,
         user: schemas.UserCreate) -> models.User:

app/sql/db.py

@@ -9,6 +9,7 @@ from sqlalchemy.orm import Session, sessionmaker
 from sqlalchemy.ext.declarative import declarative_base
 
 
+# Database configuration
 class SqlSettings(BaseSettings):
     db_host: str = '${REPO_NAME_SNAKE}_db'
     db_port: int = 3306
@@ -18,24 +19,31 @@ class SqlSettings(BaseSettings):
 
 sql_settings = SqlSettings()
 
+# DB connection URL
 db_url = (
     'mysql://{db_user}:{db_password}@'
     '{db_host}:{db_port}/{db_database}'
 ).format(**sql_settings.dict())
 
 
+# SQLAlchemy engine object
 engine = create_engine(db_url)
+
+# Create DB if not exists
 if not database_exists(db_url):
     create_database(db_url)
 
+# SQLAlchemy Session object
 SessionLocal = sessionmaker(
     autoflush=False,
     bind=engine,
 )
 
+# SQLAlchemy Base object
 Base = declarative_base()
 
 
+# FastAPI dependency
 async def get_db() -> AsyncGenerator[Session, None]:
     """FastAPI dependency
     returning database Session object.

app/sql/schemas.py

@@ -1,12 +1,16 @@
 from pydantic import BaseModel
 
 
+# Pydantic class for
+# INSERT queries on a User model
 class UserCreate(BaseModel):
     email: str
     name: str
     age: int
 
 
+# Pydantic class for
+# SELECT responses with User model(-s)
 class User(UserCreate):
     id: int