### Python Hello World App for Quart

Source: https://quart.palletsprojects.com/en/latest/tutorials/quickstart

A simple Quart application that returns 'hello' when accessed at the root URL. This serves as a basic example for getting started with Quart.

```python
from quart import Quart

app = Quart(__name__)

@app.route('/')
async def hello():
    return 'hello'

app.run()
```

--------------------------------

### Start Quart Application

Source: https://quart.palletsprojects.com/en/latest/tutorials/video_tutorial

Starts the Quart web server using the defined 'start' script via Poetry.

```bash
poetry run start
```

--------------------------------

### Start Quart App with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Starts the Quart video server application using the configured 'start' script via Poetry.

```console
poetry run start
```

--------------------------------

### Quart Hello World App

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/quickstart

A minimal Quart application that returns 'hello' when the root URL is accessed. This is the core Python code for the web service.

```python
from quart import Quart

app = Quart(__name__)

@app.route('/')
async def hello():
    return 'hello'

app.run()
```

--------------------------------

### Configure Poetry Script to Start App

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Configures a script named 'start' in the `pyproject.toml` file to run the Quart application. This allows the application to be started with a simple command.

```toml
[tool.poetry.scripts]
start = "blog:run"
```

--------------------------------

### Start Quart App with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Starts the Quart application using the 'start' script defined in `pyproject.toml`. This command executes the `run` function within the blog module.

```console
poetry run start
```

--------------------------------

### Start Quart Application

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Starts the Quart web server using the configured script in pyproject.toml.

```shell
poetry run start
```

--------------------------------

### Start Quart Chat App

Source: https://quart.palletsprojects.com/en/latest/tutorials/chat_tutorial

Starts the Quart chat application using the defined 'start' script via Poetry.

```bash
poetry run start
```

--------------------------------

### Install Quart using pip

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/installation

Installs the Quart web framework using pip. This is the basic installation command.

```console
pip install quart
```

--------------------------------

### Start Quart App with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/api_tutorial

Starts the Quart API server using the configured 'start' script via Poetry.

```console
poetry run start
```

--------------------------------

### Start Quart App with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/api_tutorial

Starts the Quart application using the configured 'start' script via Poetry.

```bash
poetry run start
```

--------------------------------

### Configure Start Script in pyproject.toml

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Configures a 'start' script in pyproject.toml to easily run the Quart application using Poetry.

```toml
[tool.poetry.scripts]
start = "video:run"
```

--------------------------------

### Running Quart App via Quart CLI

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/quickstart

Shows how to run a Quart application using the Quart command-line interface by setting the QUART_APP environment variable.

```console
$ export QUART_APP=hello-world:app
$ quart run
```

--------------------------------

### Define Start Script in pyproject.toml

Source: https://quart.palletsprojects.com/en/latest/tutorials/video_tutorial

Configures a 'start' script in pyproject.toml to easily run the Quart application using Poetry.

```toml
[tool.poetry.scripts]
start = "video:run"
```

--------------------------------

### Running Quart App via Python Script

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/quickstart

Demonstrates how to execute a Quart application directly using the Python interpreter.

```console
python hello-world.py
```

--------------------------------

### Testing Quart App with cURL

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/quickstart

Provides a command-line instruction using cURL to send a request to the running Quart application and verify its response.

```sh
curl localhost:5000
```

--------------------------------

### Define Start Script in pyproject.toml

Source: https://quart.palletsprojects.com/en/latest/tutorials/chat_tutorial

Configures a 'start' script in pyproject.toml to easily run the Quart chat application.

```toml
[tool.poetry.scripts]
start = "chat:run"
```

--------------------------------

### Start Chat Server with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/chat_tutorial

Starts the Quart chat server using a script defined in 'pyproject.toml'. The 'start' script is configured to run the 'run' function from the 'chat' package.

```console
poetry run start
```

--------------------------------

### Install Project Dependencies with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Installs all project dependencies, including Quart, as defined in the pyproject.toml file using Poetry.

```console
poetry install
```

--------------------------------

### Install Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Installs Poetry, a dependency management tool for Python projects, using pip.

```shell
pip install poetry
```

--------------------------------

### Install Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Installs Poetry, a dependency management tool for Python projects, using pip.

```console
pip install poetry
```

--------------------------------

### Install Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/video_tutorial

Installs Poetry, a dependency management tool for Python projects, using pip.

```bash
pip install poetry
```

--------------------------------

### Install Quart

Source: https://quart.palletsprojects.com/en/latest/tutorials/installation

Installs the Quart web framework using pip. Quart requires Python 3.9 or higher.

```bash
pip install quart
```

--------------------------------

### Quart App Example

Source: https://quart.palletsprojects.com/en/latest/tutorials/deployment

A basic Quart application with a single route that returns 'Hello World'. This serves as a minimal example for demonstrating Quart's functionality.

```python
from quart import Quart

app = Quart(__name__)

@app.route('/')
async def hello():
    return 'Hello World'
```

--------------------------------

### Configure Poetry Scripts for Blog

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Defines scripts in pyproject.toml for starting the Quart application and initializing the database.

```toml
[tool.poetry.scripts]
start = "blog:run"
```

--------------------------------

### Install Project Dependencies with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/video_tutorial

Installs all project dependencies defined in pyproject.toml using Poetry, ensuring the environment is set up correctly.

```bash
poetry install
```

--------------------------------

### Install Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Installs the Poetry dependency management tool using pip. This is a prerequisite for managing project dependencies in the tutorial.

```console
pip install poetry
```

--------------------------------

### Install Quart with dotenv support

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/installation

Installs Quart along with the 'dotenv' extra, which includes the 'python-dotenv' package for automatic environment variable loading.

```console
pip install quart[dotenv]
```

--------------------------------

### Install Project Dependencies with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Installs all project dependencies defined in pyproject.toml using Poetry, ensuring the correct versions are set up.

```shell
poetry install
```

--------------------------------

### Install Project Dependencies with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Installs all project dependencies defined in the pyproject.toml file using Poetry. This command ensures that the project has all necessary libraries, including Quart.

```console
poetry install
```

--------------------------------

### Configure Start Script in pyproject.toml

Source: https://quart.palletsprojects.com/en/latest/tutorials/api_tutorial

Configures a 'start' script in pyproject.toml to easily run the Quart application using Poetry.

```toml
[tool.poetry.scripts]
start = "api:run"
```

--------------------------------

### Install Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/chat_tutorial

Installs Poetry, a dependency management tool for Python projects, using pip.

```bash
pip install poetry
```

--------------------------------

### Configure Start Script in pyproject.toml

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/api_tutorial

Configures a 'start' script in pyproject.toml to easily run the Quart application using Poetry.

```toml
[tool.poetry.scripts]
start = "api:run"
```

--------------------------------

### Test Quart App Locally with `curl`

Source: https://quart.palletsprojects.com/en/latest/_sources/how_to_guides/developing

Provides an example of using the `curl` command-line tool to test a locally running Quart application. It demonstrates making a GET request to the root URL (`/`) with verbose output enabled using the `-v` flag.

```console
$ curl -v localhost:5000/
```

--------------------------------

### Configure Start Script in pyproject.toml

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/chat_tutorial

Configures a 'start' script in the 'pyproject.toml' file for the Poetry project. This script is used to run the Quart chat application.

```toml
[tool.poetry.scripts]
start = "chat:run"
```

--------------------------------

### Install Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/api_tutorial

Installs Poetry, a dependency management and packaging tool for Python, using pip.

```bash
pip install poetry
```

--------------------------------

### Install Project Dependencies with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/chat_tutorial

Installs all project dependencies defined in pyproject.toml using Poetry, ensuring paths are correct.

```bash
poetry install
```

--------------------------------

### Install Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/api_tutorial

Installs Poetry, a dependency management tool for Python projects, using pip.

```console
pip install poetry
```

--------------------------------

### Define Quart App and Run Function

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Defines the main Quart application instance and a `run` function to start the server. This code is typically placed in the project's main application file.

```python
from quart import Quart

app = Quart(__name__)

def run() -> None:
    app.run()
```

--------------------------------

### Update Poetry Scripts for Database Initialization

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Updates the `pyproject.toml` file to include a new script 'init_db' for initializing the database, alongside the existing 'start' script.

```toml
[tool.poetry.scripts]
init_db = "blog:init_db"
start = "blog:run"
```

--------------------------------

### Quart App Initialization

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Initializes a basic Quart application and defines a run function to start the server. This is the core of the web server.

```python
from quart import Quart

app = Quart(__name__)

def run() -> None:
    app.run()
```

--------------------------------

### Define Quart App and Run Function

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/chat_tutorial

Creates a Quart application instance and defines a 'run' function to start the server. This is the main entry point for the chat application.

```python
from quart import Quart

app = Quart(__name__)

def run() -> None:
    app.run()
```

--------------------------------

### Install pytest-asyncio

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Installs pytest-asyncio as a development dependency using Poetry, required for running asynchronous tests.

```console
poetry add --dev pytest-asyncio
```

--------------------------------

### Install Project Dependencies with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/chat_tutorial

Installs all project dependencies defined in 'pyproject.toml' using Poetry. This command ensures the project has all necessary libraries.

```console
poetry install
```

--------------------------------

### Install Project Dependencies with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/api_tutorial

Installs all project dependencies defined in pyproject.toml using Poetry, ensuring paths are correct.

```bash
poetry install
```

--------------------------------

### Install Quart-Schema with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/api_tutorial

Installs the Quart-Schema extension using Poetry to enable schema validation and OpenAPI documentation.

```console
poetry add quart-schema
```

--------------------------------

### Quart App Initialization

Source: https://quart.palletsprojects.com/en/latest/tutorials/video_tutorial

Initializes a basic Quart application and defines a run function to start the server. This is the core of the web server.

```python
from quart import Quart

app = Quart(__name__)

def run() -> None:
    app.run()
```

--------------------------------

### Install pytest-asyncio with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/api_tutorial

Installs the pytest-asyncio development dependency using the Poetry package manager.

```console
poetry add --dev pytest-asyncio
```

--------------------------------

### Install Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/chat_tutorial

Installs the Poetry dependency management tool using pip. Poetry is used for creating and managing Python projects.

```console
pip install poetry
```

--------------------------------

### Install pytest-asyncio

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

This console command installs the pytest-asyncio package, which is required for running asynchronous tests with pytest.

```console
poetry add --dev pytest-asyncio
```

--------------------------------

### Install Project Dependencies with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/api_tutorial

Installs all project dependencies defined in pyproject.toml using Poetry, ensuring correct paths and availability.

```console
poetry install
```

--------------------------------

### Initialize Quart App

Source: https://quart.palletsprojects.com/en/latest/tutorials/api_tutorial

Initializes a Quart application instance and defines a run function to start the server.

```python
from quart import Quart

app = Quart(__name__)

def run() -> None:
    app.run()
```

--------------------------------

### Install pytest-asyncio (Bash)

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

This command installs the pytest-asyncio package as a development dependency using Poetry. This package is necessary for running asynchronous tests with pytest.

```bash
poetry add --dev pytest-asyncio
```

--------------------------------

### Install Pytest-Asyncio

Source: https://quart.palletsprojects.com/en/latest/tutorials/chat_tutorial

This command installs `pytest-asyncio` as a development dependency using poetry. This package is required for running asynchronous tests with pytest.

```bash
poetry add --dev pytest-asyncio

```

--------------------------------

### Install pytest-asyncio

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/chat_tutorial

This console command installs the pytest-asyncio development dependency using Poetry, which is necessary for running asynchronous tests with pytest.

```console
poetry add --dev pytest-asyncio
```

--------------------------------

### Running a Quart App

Source: https://quart.palletsprojects.com/en/latest/tutorials/quickstart

Demonstrates two methods for running a Quart application: directly using the Python interpreter or by setting an environment variable and using the Quart CLI. Both methods are suitable for development.

```bash
python hello-world.py
```

```bash
$ export QUART_APP=hello-world:app
$ quart run
```

--------------------------------

### Install Quart with Dotenv Support

Source: https://quart.palletsprojects.com/en/latest/tutorials/installation

Installs Quart with the 'dotenv' extra, which includes the python-dotenv package for automatic environment variable loading.

```bash
pip install quart[dotenv]
```

--------------------------------

### Basic Quart App Setup

Source: https://quart.palletsprojects.com/en/latest/reference/cheatsheet

Sets up a basic Quart application with a single route '/hello' that returns 'Hello, World!' and runs the app in debug mode.

```Python
from quart import Quart

app = Quart(__name__)

@app.route("/hello")
async def hello():
    return "Hello, World!"

if __name__ == "__main__":
    app.run(debug=True)

```

--------------------------------

### Quart Route Handler for Creating Posts

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

This Python code defines a Quart route handler for '/create/' that accepts both GET and POST requests. For POST requests, it inserts blog post data into the database and redirects to the posts page. For GET requests, it renders the 'create.html' template.

```python
from quart import redirect, request, url_for

@app.route("/create/", methods=["GET", "POST"])
async def create():
    if request.method == "POST":
        db = _get_db()
        form = await request.form
        db.execute(
            "INSERT INTO post (title, text) VALUES (?, ?)",
            [form["title"], form["text"]],
        )
        db.commit()
        return redirect(url_for("posts"))
    else:
        return await render_template("create.html")
```

--------------------------------

### Add Quart Dependency with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Adds Quart as a project dependency using Poetry. This command ensures that Quart is installed and managed within the project's virtual environment.

```console
poetry add quart
```

--------------------------------

### Add Quart Dependency with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/chat_tutorial

Adds Quart as a project dependency using Poetry. This ensures Quart is installed and managed within the project's environment.

```console
poetry add quart
```

--------------------------------

### Quart Route for Displaying Posts

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Defines a GET route for the root URL ('/') that queries the database for posts and renders them using the 'posts.html' template.

```python
from quart import render_template, g

def _get_db():
    if not hasattr(g, "sqlite_db"):
        g.sqlite_db = _connect_db()
    return g.sqlite_db

@app.get("/")
async def posts():
    db = _get_db()
    cur = db.execute(
        """SELECT title, text
             FROM post
         ORDER BY id DESC""",
    )
    posts = cur.fetchall()
    return await render_template("posts.html", posts=posts)
```

--------------------------------

### Testing a Quart App with Curl

Source: https://quart.palletsprojects.com/en/latest/tutorials/quickstart

Shows how to test a running Quart application using the `curl` command. This command sends a request to the local server and displays the response.

```bash
curl localhost:5000
```

--------------------------------

### Initialize Quart App

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Creates a basic Quart application instance and a run function for the web server.

```python
from quart import Quart

app = Quart(__name__)

def run() -> None:
    app.run()
```

--------------------------------

### Use curl for HTTP/2 Communication

Source: https://quart.palletsprojects.com/en/latest/_sources/how_to_guides/using_http2

An example of how to use the curl command-line tool to communicate with a server over HTTP/2. Ensure that HTTP/2 support is installed for curl.

```console
$ curl --http2 ...
```

--------------------------------

### Run Database Initialization Command

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Executes the 'init_db' script using Poetry to create and update the blog's SQLite database based on the defined schema.

```console
poetry run init_db
```

--------------------------------

### Add Background Task on App Startup

Source: https://quart.palletsprojects.com/en/latest/how_to_guides/background_tasks

Shows how to schedule a background task to run when the Quart application starts. This is useful for initializing services or performing setup operations that can run in the background.

```python
async def background_task():
    ...

@app.before_serving
async def startup():
    app.add_background_task(background_task)
```

--------------------------------

### Load Environment Variables with Prefix in Quart

Source: https://quart.palletsprojects.com/en/latest/_sources/how_to_guides/configuration

Demonstrates how to load environment variables into Quart's configuration using `from_prefixed_env`. Only variables starting with the specified prefix (default 'QUART_') are loaded. This example shows setting the 'TESTING' variable.

```python
app = Quart(__name__)
app.config.from_prefixed_env()
assert app.config["TESTING"] is True
```

--------------------------------

### Quart SSE Streaming Route

Source: https://quart.palletsprojects.com/en/latest/how_to_guides/server_sent_events

An example of a Quart GET route that serves Server Sent Events. It checks for the 'text/event-stream' accept type, defines a generator to yield encoded events, and configures the response headers and timeout for streaming.

```Python
from quart import abort, make_response

@app.get("/sse")
async def sse():
    if "text/event-stream" not in request.accept_mimetypes:
        abort(400)

    async def send_events():
        while True:
            data = ...  # Up to you where the events are from
            event = ServerSentEvent(data)
            yield event.encode()

    response = await make_response(
        send_events(),
        {
            'Content-Type': 'text/event-stream',
            'Cache-Control': 'no-cache',
            'Transfer-Encoding': 'chunked',
        },
    )
    response.timeout = None
    return response
```

--------------------------------

### Run Database Initialization

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Executes the 'init_db' script to create the database and its tables.

```shell
poetry run init_db
```

--------------------------------

### Quart SSE Endpoint with Streaming

Source: https://quart.palletsprojects.com/en/latest/_sources/how_to_guides/server_sent_events

An example Quart GET route that serves Server-Sent Events. It checks for the 'text/event-stream' accept type, defines an asynchronous generator to yield encoded events, and configures the response with appropriate headers and disabled timeout.

```python
from quart import abort, make_response

@app.get("/sse")
async def sse():
    if "text/event-stream" not in request.accept_mimetypes:
        abort(400)

    async def send_events():
        while True:
            data = ...  # Up to you where the events are from
            event = ServerSentEvent(data)
            yield event.encode()

    response = await make_response(
        send_events(),
        {
            'Content-Type': 'text/event-stream',
            'Cache-Control': 'no-cache',
            'Transfer-Encoding': 'chunked',
        },
    )
    response.timeout = None
    return response
```

--------------------------------

### Initialize Database and Schema

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Connects to the SQLite database, executes the schema SQL, and commits the changes.

```python
from pathlib import Path
from sqlite3 import dbapi2 as sqlite3

app.config.update({
  "DATABASE": Path(app.root_path) / "blog.db",
})

def _connect_db():
    engine = sqlite3.connect(app.config["DATABASE"])
    engine.row_factory = sqlite3.Row
    return engine

def init_db():
    db = _connect_db()
    with open(Path(app.root_path) / "schema.sql", mode="r") as file_:
        db.cursor().executescript(file_.read())
    db.commit()
```

--------------------------------

### Create New Video Project with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Creates a new Python project structure for a video server using Poetry.

```console
poetry new --src video
```

--------------------------------

### Create New Blog Project with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Creates a new Python project structure for a blog using Poetry, with source files in a 'src' directory.

```shell
poetry new --src blog
```

--------------------------------

### Initialize Database with Schema

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Initializes the SQLite database by executing the SQL schema defined in `schema.sql`. This function reads the schema file and applies it to the database.

```python
def init_db():
    db = _connect_db()
    with open(Path(app.root_path) / "schema.sql", mode="r") as file_:
        db.cursor().executescript(file_.read())
    db.commit()
```

--------------------------------

### Update Poetry Scripts for Database Initialization

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Adds the 'init_db' script to pyproject.toml for creating and updating the database.

```toml
[tool.poetry.scripts]
init_db = "blog:init_db"
start = "blog:run"
```

--------------------------------

### Create New Python Project with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/video_tutorial

Creates a new Python project structure using Poetry, with the source code in a 'src' directory.

```bash
poetry new --src video
```

--------------------------------

### Configure Database Path and Connection

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Configures the database path for the Quart application and provides a helper function `_connect_db` to establish a connection to the SQLite database. It also sets the row factory for convenient data access.

```python
from pathlib import Path
from sqlite3 import dbapi2 as sqlite3

app.config.update({
  "DATABASE": Path(app.root_path) / "blog.db",
})

def _connect_db():
    engine = sqlite3.connect(app.config["DATABASE"])
    engine.row_factory = sqlite3.Row
    return engine
```

--------------------------------

### Run Tests with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Executes all tests in the 'tests/' directory using Poetry, ensuring the video server functions correctly.

```console
poetry run pytest tests/
```

--------------------------------

### Quart Startup and Shutdown Decorators

Source: https://quart.palletsprojects.com/en/latest/how_to_guides/startup_shutdown

Demonstrates the use of Quart's `before_serving`, `while_serving`, and `after_serving` decorators to manage application startup and shutdown logic, including database pool creation and cleanup. It also shows how to use `g` within these contexts.

```python
from quart import g

@app.before_serving
async def create_db_pool():
    app.db_pool = await ...
    g.something = something

@app.before_serving
async def use_g():
    g.something.do_something()

@app.while_serving
async def lifespan():
    ...  # startup
    yield
    ...  # shutdown

@app.route("/")
async def index():
    app.db_pool.execute(...)
    # g.something is not available here

@app.after_serving
async def create_db_pool():
    await app.db_pool.close()
```

--------------------------------

### Add Quart Dependency with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/blog_tutorial

Adds Quart as a project dependency using Poetry, ensuring it's available for the blog server.

```shell
poetry add quart
```

--------------------------------

### Create New Python Project with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/chat_tutorial

Creates a new Python project named 'chat' with a src layout using Poetry.

```bash
poetry new --src chat
```

--------------------------------

### Quart 0.18.0: Adopt Flask’s logging setup

Source: https://quart.palletsprojects.com/en/latest/changes

Quart has adopted Flask's logging setup, ensuring a consistent and familiar logging experience for developers transitioning between the frameworks.

```Python
import logging

logging.basicConfig(level=logging.INFO)
# Quart now uses Flask's logging configuration style

```

--------------------------------

### Quart JSON Responses

Source: https://quart.palletsprojects.com/en/latest/_sources/reference/cheatsheet

Provides an example of how to return JSON data directly from a Quart route handler.

```python
@app.route("/hello")
async def hello():
    return {"Hello": "World!"}
```

--------------------------------

### Add Quart Dependency with Poetry

Source: https://quart.palletsprojects.com/en/latest/tutorials/video_tutorial

Adds Quart as a project dependency using Poetry, ensuring it's available for the video server.

```bash
poetry add quart
```

--------------------------------

### Get Response Body as JSON

Source: https://quart.palletsprojects.com/en/latest/reference/source/quart

Parses the response body as JSON. The `force` parameter allows parsing even if the mimetype is not JSON.

```python
json_data = await response.get_json()
json_data_forced = await response.get_json(force=True)
```

--------------------------------

### Get Response Body Data

Source: https://quart.palletsprojects.com/en/latest/reference/source/quart

Retrieves the response body data as bytes or text. The `as_text` parameter controls the return type.

```python
data_bytes = await response.get_data(as_text=False)
data_text = await response.get_data(as_text=True)
```

--------------------------------

### Quart Request Methods

Source: https://quart.palletsprojects.com/en/latest/reference/cheatsheet

Shows how to specify allowed HTTP request methods for routes in Quart. By default, routes accept GET requests.

```Python
@app.route("/get")  # GET Only by default
@app.route("/get", methods=["GET", "POST"])  # GET and POST
@app.route("/get", methods=["DELETE"])  # Just DELETE

```

--------------------------------

### Add Quart Dependency with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/video_tutorial

Adds Quart as a project dependency using Poetry, ensuring it's available for the video server.

```console
poetry add quart
```

--------------------------------

### Quart Request Methods

Source: https://quart.palletsprojects.com/en/latest/_sources/reference/cheatsheet

Illustrates how to specify allowed HTTP request methods for a given route in Quart, defaulting to GET if not explicitly defined.

```python
@app.route("/get")  # GET Only by default
@app.route("/get", methods=["GET", "POST"])  # GET and POST
@app.route("/get", methods=["DELETE"])  # Just DELETE
```

--------------------------------

### Quart App Initialization

Source: https://quart.palletsprojects.com/en/latest/tutorials/chat_tutorial

Initializes a basic Quart application instance and defines a run method for the server.

```python
from quart import Quart

app = Quart(__name__)

def run() -> None:
    app.run()
```

--------------------------------

### Blueprint Context Processor

Source: https://quart.palletsprojects.com/en/latest/how_to_guides/templating

Example of defining a context processor specifically for a blueprint, making the provided context available only to routes within that blueprint.

```Python
from quart import Blueprint

blueprint = Blueprint(__name__)

@blueprint.context_processor
async def blueprint_only():
    return {'context': 'value'}
```

--------------------------------

### Communicate via HTTP/2 with curl

Source: https://quart.palletsprojects.com/en/latest/how_to_guides/using_http2

Shows how to use the `curl` command-line tool to communicate via HTTP/2. This requires `curl` to be installed with HTTP/2 support.

```bash
$ curl --http2 ...
```

--------------------------------

### Run Quart with Hypercorn

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/deployment

This snippet shows how to create a basic Quart application and run it using the Hypercorn ASGI server. Hypercorn is recommended for production deployments over Quart's development server.

```python
from quart import Quart

app = Quart(__name__)

@app.route('/')
async def hello():
    return 'Hello World'
```

```bash
hypercorn example:app
```

--------------------------------

### Application-Wide Context Processor

Source: https://quart.palletsprojects.com/en/latest/how_to_guides/templating

Example of defining a context processor that applies to all requests handled by the Quart application, making the provided context globally available.

```Python
from quart import Blueprint

blueprint = Blueprint(__name__)

@blueprint.app_context_processor
async def app_wide():
    return {'context': 'value'}
```

--------------------------------

### Return JSON Array with jsonify

Source: https://quart.palletsprojects.com/en/latest/tutorials/api_tutorial

Demonstrates using Quart's `jsonify` function to return a JSON array from a GET route.

```python
from quart import jsonify

@app.get("/example")
async def example():
    return jsonify(["a", "b"])
```

--------------------------------

### Create New Blog Project with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/blog_tutorial

Creates a new Python project structure for the blog using the Poetry command-line tool. The `--src` flag indicates that the source code will be in a 'src' directory.

```console
poetry new --src blog
```

--------------------------------

### Test Streaming Request and Response

Source: https://quart.palletsprojects.com/en/latest/how_to_guides/testing

Provides an example of testing routes that handle streaming requests and responses using the test client's request method.

```python
async def test_stream() -> None:
    test_client = app.test_client()
    async with test_client.request(...) as connection:
        await connection.send(b"data")
        await connection.send_complete()
        ...
        # receive a chunk of the response
        data = await connection.receive()
        ...
    # assemble the rest of the response without the first bit
    response = await connection.as_response()

```

--------------------------------

### Quart Route for Conditional Video Serving

Source: https://quart.palletsprojects.com/en/latest/tutorials/video_tutorial

Implements a route for '/video.mp4' that serves the video file with conditional GET requests enabled, allowing for range requests.

```python
from quart import send_file

@app.route("/video.mp4")
async def auto_video():
    return await send_file(app.static_folder / "video.mp4", conditional=True)
```

--------------------------------

### Serve Chat UI from Root Path

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/chat_tutorial

Adds a route to the Quart application to serve the 'index.html' template for the root path ('/'). This makes the chat UI accessible to users.

```python
from quart import render_template

@app.get("/")
async def index():
    return await render_template("index.html")
```

--------------------------------

### Basic Test Client Usage in Quart

Source: https://quart.palletsprojects.com/en/latest/_sources/how_to_guides/testing

Demonstrates how to create a test client for a Quart app and make a GET request to the root path, asserting the response status code.

```python
async def test_app(app):
    client = app.test_client()
    response = await client.get('/')
    assert response.status_code == 200
```

--------------------------------

### Create New API Project with Poetry

Source: https://quart.palletsprojects.com/en/latest/_sources/tutorials/api_tutorial

Creates a new Python project structure for an API server using the Poetry command-line tool.

```console
poetry new --src api
```