This Python Flask tutorial will introduce you to the essential concepts that you’ll need to get started on your web development journey. It covers creating static files, setting up a secret key, and adding variables to a URL. In the end, you’ll be able to create a fully-functional web application.
Table of Contents
Creating a static file
If you want to serve static files in your Flask application, you will first need to create a static file in the application root directory. Then, you can reference the static file using relative file paths or absolute URL references by using the url_for() function. To create an absolute URL reference, you simply specify the directory or filename and then the name of the static file. When you are done, Flask will automatically create a static view for you.
You can also use a static site generator to create a static site. These tools parse markdown content and generate a static file. Popular options include Jekyll, Eleventy, Gatsby, and Hugo. Another alternative is Flask with Frozen-Flask, which allows you to test static sites.
Static files are crucial for the look of a website. Static files can contain several different files. These files are stored in a folder along with the significant flask app. Static files can contain images, javascript, and CSS files.
Adding variables to a URL
You can easily add variables to a URL with Flask. Its built-in debugger gives you detailed error messages, which is extremely useful when troubleshooting. Typically, you will want to run your Flask application locally at the URL http://127.0.0.1:5000/, where 127.0.0.1 is the local host on your machine and.5000 is the port number on which the application is running.
In most cases, you won’t need to add route-related logic to your Flask application. Instead, you can simply use the add_url() function from Flask. You will need to pass this function the variable name you want to include.
Flask is a micro web framework built with Python. It’s designed to help you create an API without writing much code. It’s lightweight and extensible, which makes it an ideal solution for new developers.
Setting a secret key.
You are not alone if you have been wondering about setting a secret key in your Python flask application. This is something that a lot of developers face. Fortunately, Flask recognizes the variables and implements them automatically. The key here is that the secrets are not exposed to other parts of your application in files. Instead, the standard solution is to pull the values from an environment variable such as development mode or production mode. Setting the environment to development mode automatically sets DEBUG to True, which will cause many Flask plugins to behave differently in the development mode.
To use Flask’s secret key, you must first set a private key in your project’s instance folder. This is important because Flask uses this secret key to sign cookies. Moreover, it is used by other extensions such as Flask-Bcrypt. When setting a secret key in Flask, you should specify a complex random value instead of a single-word value.
Using Jinja2
When using Python Flask, you’ll want to use the template engine, Jinja. Jinja is a templating language that renders HTML. It also provides a range of valuable features, including dynamic content, if statements, loops, filters, and template inheritance. You can also use keyword arguments in your template to support application variables.
A template variable is used as a placeholder for data. The url_for() function identifies routes within a template. However, be aware that URL strings may change because of changes on the site. To avoid this problem, call the template engine’s url_for() function within an expression delimiter. Alternatively, you can add keyword arguments to the call to pass variables to the Flask app route.
Jinja2 has a powerful inheritance system. It allows you to use multiple templates for your site. Each template can inherit from the others and is made of several parts. In addition, you can override certain parts of the base template using child templates. Each child template can include a separate template for different types of content, and it can be used to replace any code between the base template’s title and the content block. When using child templates, ensure that the name of the content block is unique across templates.
