Quickstart for Python App Engine Standard Environment

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This quickstart shows you how to create a small App Engine application that displays a short message.

Before you begin

Before running and deploying this quickstart, you must install the Cloud SDK and create or use an existing Cloud Platform Console project:

Create a new Cloud Platform Console project or retrieve the project ID of an existing project from the Google Cloud Platform Console:

Go to the Projects page

Tip: Retrieve a list of your existing project IDs with gcloud.
To install the gcloud tool, you install and then initialize the Google Cloud SDK:

Download the SDK

Listing your Cloud Platform Console project IDs with `gcloud`

From the command line, run:

gcloud projects list

Download the Hello World app

We've created a simple Hello World app for Python so you can quickly get a feel for deploying an app to Google Cloud Platform. Follow these steps to download Hello World to your local machine.

Clone the Hello World sample app repository to your local machine:

git clone https://github.com/GoogleCloudPlatform/python-docs-samples

Then go to the directory that contains the sample code:

cd python-docs-samples/appengine/standard/hello_world

Alternatively, you can download the sample as a zip file and extract it.

Test the application

Test the application using the local development server (dev_appserver.py), which is included with the SDK.

From within the hello_world directory, start the local development server with the following command:
```
dev_appserver.py app.yaml
```
The local development server is now running and listening for requests on port 8080.
Visit http://localhost:8080/ in your web browser to view the app.

For more information about running the local development server, see the Python Development Server reference.

Running the local development server (`dev_appserver.py`)

To run the local development server, you can either run dev_appserver.py by specifying the full directory path or you can add dev_appserver.py to your PATH environment variable:

If you installed the App Engine SDK, the tool is located at [PATH_TO_APP_ENGINE_SDK]/dev_appserver.py.
If you installed the Google Cloud SDK, the tool is located at [PATH_TO_CLOUD_SDK]/google-cloud-sdk/bin/dev_appserver.py.

Tip: To add the Google Cloud SDK tools to your PATH environment variable and enable command-completion in your shell, you can run:
```
[PATH_TO_CLOUD_SDK]/google-cloud-sdk/install.sh
```

Make a change

You can leave the development server running while you develop your application. The development server watches for changes in your source files and reloads them if necessary.

Try it now: Leave the development server running, then edit main.py to change Hello, World! to something else.
Reload http://localhost:8080/ to see the results.

Deploy your app

To deploy your app to App Engine, run the following command from within the root directory of your application where the app.yaml file is located:

gcloud app deploy

Optional flags:

Include the --project flag to specify an alternate Cloud Platform Console project ID to what you initialized as the default in the gcloud tool. Example: --project [YOUR_PROJECT_ID]
Include the -v flag to specify a version ID, otherwise one is generated for you. Example: -v [YOUR_VERSION_ID]

To learn more about deploying your app from the command line, see Deploying a Python App.

View your application

To launch your browser and view the app at http://[YOUR_PROJECT_ID].appspot.com, run the following command:

gcloud app browse

Congratulations!

You have completed this quickstart.

See the following sections for information about cleaning up after this quickstart as well as links to the possible next steps you can take with your deployed applications.

To learn more about this Hello World app, see the Hello World code review section.

Clean up

To avoid incurring charges to your Google Cloud Platform account for the resources used in this quickstart:

Go to the Cloud Platform Console.
In the list of projects, select the project that you want to shut down.
In the prompt, type your project ID to confirm the deletion.
Click Shut down to schedule your project for deletion.

What's next

Develop a basic Flask app

Learn how to develop and deploy basic Python 2.7 applications that run on the Google App Engine Standard Environment. If you're new to Google App Engine, its related services, and in particular, using App Engine with the Python language, the Flask guide provides deeper explanations for each task than what is found in the Quickstart guide. For more information, see Getting Started with Flask on App Engine Standard Environment.

Use a custom domain

You can serve your App Engine app using your own custom domain instead of appspot.com. For more information, see Using Custom Domains and SSL.

Hello World code review

Hello World is the simplest possible App Engine app: it contains only one service, has only one version, and all of the code is located within the app's root directory. This section describes each of the app files in detail.

`main.py`

This Python script responds to a request with an HTTP header and the message Hello, World!.

appengine/standard/hello_world/main.py

View on GitHub

import webapp2


class MainPage(webapp2.RequestHandler):
    def get(self):
        self.response.headers['Content-Type'] = 'text/plain'
        self.response.write('Hello, World!')


app = webapp2.WSGIApplication([
    ('/', MainPage),
], debug=True)

`app.yaml`

The app.yaml configuration file defines several options for the app, and describes which handler scripts should be used for which URLs.

appengine/standard/hello_world/app.yaml

View on GitHub

runtime: python27
api_version: 1
threadsafe: true

handlers:
- url: /.*
  script: main.app

From top to bottom, this configuration file says the following about this application:

This code runs in the python27 runtime environment, API version 1.
This application is threadsafe so the same instance can handle several simultaneous requests. Threadsafe is an advanced feature and can result in erratic behavior if your application is not specifically designed to be threadsafe.
Every request to a URL whose path matches the regular expression /.* (all URLs) should be handled by the app object in the main Python module.

The syntax of this file is YAML. For a complete list of configuration options, see the app.yaml reference.

Learn more

Learn the whole platform

Now that you know what it's like to develop and deploy App Engine apps, you can stretch out and see the rest of Google Cloud Platform. For a guided walkthrough that teaches you how to create an application that uses the entire platform, not just App Engine, check out our Creating a Guestbook quickstart in which you expand this simple application to become a fully-fledged Guestbook application that lets authenticated Google accounts post messages to a public page.

Creating a Guestbook

Learn more about App Engine standard environment

Here are some topics to help you to continue learning about App Engine.

Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates.

Last updated January 9, 2017.