Python jinja2 for Loop Example

Categories Python

An example of a for loop using Jinja2, a popular templating engine for Python:

from jinja2 import Template

# Define the template string
template_str = """
<ul>
{% for item in items %}
  <li>{{ item }}</li>
{% endfor %}
</ul>
"""

# Create a Jinja2 template object
template = Template(template_str)

# Define the data for rendering
data = {
    'items': ['Apple', 'Banana', 'Orange']
}

# Render the template with the data
output = template.render(data)

# Print the rendered output
print(output)
Code language: Python (python)

In this example, we create a Jinja2 template using the template string. Inside the template, we use the {% for %} and {% endfor %} tags to define a for loop. The loop iterates over the items list in the data dictionary and renders an HTML list item (<li>) for each item.

After rendering the template with the data using template.render(data), we store the output in the output variable. Finally, we print the rendered output, which displays an unordered list (<ul>) with each item in a separate list item.

You can modify the template and data to suit your specific use case.

How to use Jinja2 in Python?

To use Jinja2 in Python, you need to follow these steps:

1. Install Jinja2: You can install Jinja2 using pip by running the following command in your terminal:

pip install Jinja2Code language: Python (python)

2. Import the Jinja2 module: In your Python script, import the jinja2 module using the import statement:

from jinja2 import TemplateCode language: Python (python)

3. Define a template: Create a template string or load a template file. You can use placeholders, conditionals, loops, and other Jinja2 features to define the template structure and logic.

4. Create a Jinja2 template object: Use the Template class from Jinja2 to create a template object from your template string or file:

template = Template(template_str)Code language: Python (python)

Note: If you’re loading a template from a file, you can use the Environment class instead:

from jinja2 import Environment, FileSystemLoader

env = Environment(loader=FileSystemLoader('/path/to/templates'))
template = env.get_template('template_name.html')Code language: Python (python)

5. Provide data for rendering: Prepare the data that you want to pass to the template for rendering. This can be a dictionary, object, or any other data structure that you want to use within the template.

6. Render the template: Use the render() method on the template object to render the template with the provided data:

output = template.render(data)Code language: Python (python)

7. Process or display the output: The output variable will contain the rendered template output. You can process it further or display it as needed.

Here’s an example that puts these steps together:

from jinja2 import Template

# Define the template string
template_str = """
Hello, {{ name }}!
"""

# Create a Jinja2 template object
template = Template(template_str)

# Define the data for rendering
data = {
    'name': 'John'
}

# Render the template with the data
output = template.render(data)

# Print the rendered output
print(output)
Code language: Python (python)

This example renders a simple template that greets a person by name. The data dictionary provides the value for the name placeholder in the template. The rendered output is then printed to the console.

You can customize the template, data, and output handling based on your specific requirements.

What is the alternative to Jinja2 in Python?

While Jinja2 is a popular and widely-used templating engine in Python, there are a few alternative templating engines you can consider based on your specific needs and preferences. Here are a few alternatives to Jinja2:

  • Django Templates: Django, a high-level Python web framework, comes with its own built-in templating engine called Django Templates. If you’re working within the Django framework, using Django Templates can be a seamless choice. It offers a syntax similar to Jinja2 and integrates well with other Django features.
  • Tornado Templates: Tornado is a Python web framework known for its asynchronous and non-blocking capabilities. Tornado includes its own templating engine called Tornado Templates. It offers a simple and easy-to-use syntax, suitable for building asynchronous web applications.
  • Cheetah: Cheetah is a template engine that focuses on providing a high-performance solution. It offers a template language that closely resembles Python syntax and supports features like inheritance, loops, and conditionals. Cheetah templates are compiled into Python modules for efficient execution.
  • Genshi: Genshi is an XML-based templating engine that emphasizes separation of concerns. It uses XML or HTML templates and provides powerful features like template inheritance, component-based development, and XML transformations.

Each templating engine has its own strengths and weaknesses, so it’s important to consider your specific requirements and choose the one that best fits your project and coding style.

Is Jinja2 built in Python?

No, Jinja2 is not built into Python. It is a separate templating engine that is written in Python and designed to be used with Python applications. Jinja2 is developed as an independent project and is not part of the Python standard library.

To use Jinja2 in your Python projects, you need to install it separately by using the pip package manager. You can install Jinja2 by running the following command:

pip install Jinja2Code language: Python (python)

Once installed, you can import the Jinja2 module in your Python scripts and use it to create and render templates. Jinja2 provides a powerful and flexible templating language that allows you to generate dynamic content in a variety of formats, such as HTML, XML, JSON, and more.

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  • Dmytro Iliushko

    I am a middle python software engineer with a bachelor's degree in Software Engineering from Kharkiv National Aerospace University. My expertise lies in Python, Django, Flask, Docker, REST API, Odoo development, relational databases, and web development. I am passionate about creating efficient and scalable software solutions that drive innovation in the industry.

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