Computer Science
Grade 10
20 min
Flask Templates: Rendering Dynamic Content
Learn how to use Flask templates (Jinja2) to render dynamic content.
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Explain the difference between static and dynamic web content.
Pass variables from a Python Flask route to an HTML template.
Use Jinja2 syntax to display variables within an HTML file.
Implement control structures, such as for-loops and if-statements, inside a template.
Iterate over a list or dictionary from Python to generate dynamic HTML lists or tables.
Structure a simple Flask application with a dedicated 'templates' folder.
Ever wondered how a website greets you with 'Welcome, [Your Name]!' instead of a generic 'Welcome, User!'? 🤔 That's the magic of dynamic content!
In this tutorial, we'll move beyond static, unchanging HTML. You will learn how to use Flask's template engine, Jinja2, to create dynamic w...
2
Key Concepts & Vocabulary
TermDefinitionExample
Template EngineA software library that processes templates containing special syntax. It combines these templates with data from your application to generate a final document, usually HTML.Flask uses the Jinja2 template engine. When you write `<h1>Hello, {{ name }}</h1>`, Jinja2 replaces `{{ name }}` with the actual value of the 'name' variable.
Jinja2A popular and powerful template engine for Python. It's the default engine used by the Flask framework.Jinja2 provides the special syntax like `{{ ... }}` for variables and `{% ... %}` for statements like loops and conditionals.
Dynamic ContentParts of a web page that change based on variables, user input, or data from a database. It's generated on-the-fly when a user requests the page.A...
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Core Syntax & Patterns
Variable Expression
{{ variable_name }}
Use double curly braces to print the value of a variable passed from your Flask route. This is for displaying data.
Statement Delimiter
{% statement %}
Use a curly brace with a percent sign for control structures like `for` loops, `if/elif/else` conditions, and other logic. These don't directly print to the page but control how the page is built.
The `render_template()` Function
render_template('template_name.html', var1=value1, var2=value2)
This is the core Flask function used in your Python file. It takes the filename of the template (which must be in a 'templates' folder) and any number of keyword arguments, which become the variables available inside the template.
4 more steps in this tutorial
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Sign Up Free to ContinueSample Practice Questions
Easy
In a Flask application, what is the primary function of a template engine like Jinja2?
A.To handle database connections and queries.
B.To process templates with special syntax and combine them with data to generate final HTML.
C.To define the application's URL routes and endpoints.
D.To manage server-side security and user authentication.
Easy
Which Flask function is used to render an HTML file from the 'templates' folder and pass Python variables to it?
A.template.render()
B.Flask.render()
C.render_template()
D.show_template()
Easy
According to the tutorial, what is the correct Jinja2 syntax to display the value of a Python variable named `greeting` in an HTML template?
A.{% greeting %}
B.[[ greeting ]]
C.{{ greeting }}
D.( greeting )
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