One of the best ways to learn py4web is to create a free account on PythonAnywhere. While PythonAnywhere has ready-to-go presets for other frameworks, such as webp2y or Django, you'll have to install py4web yourself.
This tutorial shows you step by step how to install and run py4web. It is meant for people with limited system administration knowledge, and it shouldn't leave anything out.
Everything you need to install py4web on PythonAnywhere should be documented here. If you encounter any problems, or need something explained better, please file an issue.
You need to create a free PythonAnywhere account. They don't require a credit card, which means it's practical for developers without good access to an American payment system.
The username you create will also serve as the subdomain name on a free PythonAnywhere account. For example,
if your username is totallycoolsite then its URL will be:
http://totallycoolsite.pythonanywhere.com
Let's make sure we're on the same page, which should the the dashboard.
- Choose the PythonAnywhere logo at the top of the page to navigate to the PythonAnywhere dashboard.
You'll see a navigation menu near the top of the page that says Dashboard Consoles Files Web Tasks Databases.
One of the distinct features of py4web is that it is nothing more than a Python program. py4web apps are nothing more than a simple
directory tree structure with a few files inside an applications subdirectory, called apps by default.
This section shows how to clone the py4web repo
from GitHub. It uses the Bash command line console supplied with PythonAnywhere.
PythonAnywhere lets you run a bash console directly in your browser. That means you don't have to install and configure ssh to remote in. Just run bash from their web page. It simulates a console right there. You can perform many common tasks as if it were happening on your own desktop without having to fiddle with ssh configuration.
- From the Dashboard Consoles Files Web Tasks Databases navigation menu choose Consoles.
You'll see Start a new Console.
- Next to Other, choose Bash.
After a few seconds, the Bash prompt appears in a new browser tab. It looks roughly like this: ~ $.
The next step is to obtain a copy of the py4web distribution. The following copies the latest supported major release into its own directory.
- Enter
git clone https://github.com/web2py/py4web.gitat the prompt:
$ git clone https://github.com/web2py/py4web.gitA list of progress messages scrolls down. It looks something like this, but longer:
Cloning into 'py4web'...
remote: Enumerating objects: 167, done.
remote: Counting objects: 100% (167/167), done.
...
Checking out files: 100% (660/660), done.
04:21 ~ $
The result is a py4web subdirectory in your root directory containing the py4web source treee.
Make py4web the current directory:
$ cd py4web- Enter python3 -m pip install -U --user -r requirements.txt to install using pip:
# --U updates old modules.
# --user means install in your local directory
# Required on PythonAnywhere because you don't have
# permission to install globally.
$ python3 -m pip install -U --user -r requirements.txtNow configure py4web:
$ ./py4web.py setup apps
$ ./py4web.py set_passwordThe ./py4web.py set_password step asks you twice for a password. That will be used when you log into the py4web dashboard.
You currently have a web page open running a simulated bash console for py4web. Open a second PythonAnywhere tab.
- There's a PythonAnywhere logo at the top of the page. Right-click (or Command-Click on MacOS) that logo to open another PythonAnywhere page.
-
On the navigation bar near the top of the page that says Dashboard Consoles Files Web Tasks Databases choose Web.
-
Choose Add a new web app.
-
A dialog appears called Create a new web app
You're informed that PythonAnywhere is creating a URL for your site and displays that URL. The main part of the URL is your username followed by pythonanywhere.com.
- Choose Next.
The Select a Python Web framework dialog appears, showing a list of frameworks like web2py, Django, Bottle, and so on.
Py4web uses Bottle. So:
- Choose Bottle from the list.
You're asked to select a Python version.
- Choose Python 3.8 (Bottle doesn't work with earlier versions):
The Quickstart new Bottle Project dialog appears. You're asked to give the location where a bottle_app.py file will be generated.
It looks something like this, where your_username stands in for the PythonAnywhere username you created on signup.
Path:
/home/your_username/mysite/bottle_app.py-
Replace the
mysiteportion withpy4web. -
Replace
your_usernamewith your PythonAnywhere username.
For example:
/home/your_username/py4web/bottle_app.py- Choose Next.
You're shown a message saying All done! Your web app is now set up. Details below.
- Scroll down to the section headed Code, which shows Source Code, Working Directory, and other information.
- Click the URL next to Source Code. It is made editable. Make sure the end contains your URL followed by
/py4webintead of/mysite. Replaceyour_usernamein the following example with your PythonAnywhere username, and after typing in the correct values be sure to click the checkmark button to confirm your changes:
# 1. Replace your_username with your own PythonAnywhere username
# 2. Replace mysite with py4web
# 3. BE SURE to click the checkmark to confirm your change!
/home/your_username/py4web
- Do the same for Working directory.
The WSGI configuration needs your project's home directory updated from its default value. Just under Source code and Working directory you'll see WSGI configuration file. You can open up a built-in editor for it simply by clicking.
- Click the link for WSGI configuration file and your WSGI configuration file appears in an editor.
You'll see something like this, with your PythonAnywhere username in place of your_username:
project_home = '/home/your_username/mysite'
- Change it to your py4web apps folder name like this, replacing
your_usernamewith your PythonAnywhere username, and replacingmysitewithpy4web/appsMake sure it all stays within the quote marks:
project_home = '/home/your_username/py4web/apps'
- At the top of the page choose Save to preserve your changes.
- Return to the PythonAnywhere bash shell.
Run your favorite editor on the file ~/py4web/bottle_app.py:
# Replace vim with whatever editor you prefer
vim ~/py4web/bottle_app.py- Replace the contents of
bottle_app.pyas follows
import os
from py4web.core import wsgi
# BEGIN CONFIGURATION
PASSWORD_FILENAME = 'password.txt'
DASHBOARD_MODE = 'full' or 'demo' or 'none'
APPS_FOLDER = 'apps'
# END CONFIGURATION
password_file = os.path.abspath(os.path.join(os.path.dirname(__file__), PASSWORD_FILENAME))
application = wsgi(password_file=password_file,
dashboard_mode=DASHBOARD_MODE,
apps_folder=APPS_FOLDER)
- Return to the PythonAnywhere Web page
There is now a Configuration section with the name of your URL, and a big green Reload button with your URL on it.
- Choose the Reload your_username.pythonanywhere.com button, where your_username is used in place of your PythonAnywhere account name.
A progress icon appears for a few seconds, then the page returns to its previous state. You're finally ready to run py4web.
-
Return to the PythonAnywhere bash shell.
-
Start py4web like so:
$ ./py4web.py run appsThis starts the built-in py4web web server and runs its own copy of the py4web site. It is now available online at your PythonAnywhere URL.
- Return to the PythonAnywhere Web page: on the navigation bar near the top of the page that says Dashboard Consoles Files Web Tasks Databases choose Web.
Near the top you'll see Configuration for and the URL of your website in link form.
- Click your website's URL under Configuration for.
It should look like this:
To begin writing py4web apps choose Dashboard.
- You'll be asked for the password you created earlier. When you enter it you'll see the py4web dashboard:
