from jinja2 import Template

template = Template("Hello, {{ name }}! Welcome to {{ platform }}.")
output = template.render(name="Pallav", platform="IIT Gandhinagar")
print(output)

Hello, Pallav! Welcome to IIT Gandhinagar.

import jinja2  # import helps to add the required library
print("Jinja2 version:", jinja2.__version__)  # .__version__ is used to get version of the library

Jinja2 version: 3.1.5

from jinja2 import Template

template = Template("Hello, {{ name }}!")  # Creating a template
rendered = template.render(name="World")   # Rendering (combining) data (world) with template)
print(rendered)

Hello, World!

from jinja2 import Environment, FileSystemLoader 
env = Environment(loader = FileSystemLoader('.')) # . points to the current directory  
template = env.get_template('Welcome to Jinja.jinja')
output = template.render()
print(output)

Welcome to Python - HTML Interface: Jinja2 Template

with open("Welcome_Jinja2.txt", 'w') as f:
    print(output, file = f)

from jinja2 import Environment, FileSystemLoader 

# Loading the Environment
env = Environment(loader = FileSystemLoader('.')) # Takes it to the current directory  

# Loading the template
template = env.get_template('Hello World.jinja')

# Getting input from the user
n = input("Enter the name to be added in the Jinja file: ")

# Rendering the data and template
output = template.render(name=n)

# Printing the output
print(output)

Hello Pallav Biyala!

from jinja2 import Environment, FileSystemLoader 
env = Environment(loader = FileSystemLoader('C:/Programming_Files_Python_C_C++/Python Files/Jinja2 Templating/'))  
template = env.get_template('Table of number n.jinja')
output = template.render(number = 10)
print(output)

<!DOCTYPE HTML>
<html>
    <head>
        <title>
            Table of 10
        </title>
    </head>
    <body>
        <h3> Table of 10 rendered with Jinja2 Templating is:</h3>
        
        <p>10 × 1 = 10</p>
        
        <p>10 × 2 = 20</p>
        
        <p>10 × 3 = 30</p>
        
        <p>10 × 4 = 40</p>
        
        <p>10 × 5 = 50</p>
        
        <p>10 × 6 = 60</p>
        
        <p>10 × 7 = 70</p>
        
        <p>10 × 8 = 80</p>
        
        <p>10 × 9 = 90</p>
        
        <p>10 × 10 = 100</p>
        
    </body>
</html>

with open("C:/Programming_Files_Python_C_C++/Python Files/Jinja2 Templating//Table of number n.html", 'w') as f:
    print(output, file = f)

from jinja2 import Environment, FileSystemLoader

# Step 1: Set up Jinja2 Environment
env = Environment(loader=FileSystemLoader('.'))  # Current directory

# Step 2: Load the HTML Template
template = env.get_template('IITian students.jinja')

# Step 3: Data to Pass to Template
name = input("Enter your name to be added in file: ")

iits = [
    "IIT Bombay", "IIT Delhi", "IIT Roorkee", "IIT Gandhinagar", 
    "IIT Kanpur", "IIT Kharagpur", "IIT Guwahati", "IIT Indore", 
    "IIT Ropar", "IIT Hyderabad", "IIT Madras"
]

streams_n = int(input("Enter the number of streams in your IIT: "))
stream = []

for i in range(streams_n):
    stream_in_iit = input(f"Enter the name of stream {i+1}: ")  
    stream.append(stream_in_iit)

data = {
    "name": name,
    "streams": stream,  
    "iit_list": iits
}

# Step 4: Render the Template
output = template.render(data)

# Step 5: Save the Rendered HTML
with open("IITian students.html", "w") as file:
    file.write(output)

print("HTML File successfully created")

HTML File successfully created

from jinja2 import Environment, FileSystemLoader

# Step 1: Set up Jinja2 Environment
env = Environment(loader=FileSystemLoader('.'))  # Current directory

# Step 2: Load the Template
template = env.get_template('Filters Use.jinja')

# Step 3: Pass Data to Template
data = {
    'numbers': [9, 3, 5, 1, 7, 2]
}

# Step 4: Render the Template with Data
output = template.render(data)

# Step 5: Save the Rendered HTML
with open('sorted_numbers.html', 'w') as file:
    file.write(output)

print("Sorted list generated in 'sorted_numbers.html'")

Sorted list generated in 'sorted_numbers.html'

from jinja2 import Environment, FileSystemLoader

# Step 1: Set up Jinja2 Environment
env = Environment(loader=FileSystemLoader('.'))  # Current directory

# Step 2: Load the HTML Template
template = env.get_template('Basic Macros.jinja')

# Step 3: Rendering the data into html file
output = template.render()
with open("Basic Macros.html", "w") as file:
    file.write(output)

print("HTML File successfully created")

HTML File successfully created

from jinja2 import Environment, FileSystemLoader

# Step 1: Set up Jinja2 Environment
env = Environment(loader=FileSystemLoader('.'))  # Current directory

# Step 2: Load the HTML Template
template = env.get_template('Macros Button.jinja')

# Step 3: Rendering the data into html file
output = template.render()
with open("Macros Button.html", "w") as file:
    file.write(output)

print("HTML File successfully created")

HTML File successfully created

from jinja2 import Environment, FileSystemLoader

# Set up Jinja2 Environment
env = Environment(loader=FileSystemLoader('.'))

# Load child template
template = env.get_template('Child Template.jinja')

# Render and save
output = template.render()
with open("Rendered child template.html", "w") as file:
    file.write(output)

print("Rendered successfully!")

Rendered successfully!

Function	Purpose
Environment()	Acts as the core of Jinja2 — manages templates and their settings.
FileSystemLoader(<path>)	Tells Jinja2 where to find the templates. Points to the template directory.
env.get_template(<file>)	Fetches the specific template you want to render.
template.render()	Converts the template into a final text output.
print(output)	Displays the rendered output on the screen.

Delimiter	Purpose	When to use?	Example
{{...}}	It is used to output the variables or run simple expressions, i.e., it functions similar to Python's f string.	It is used when we have some function outputs, outputs of variables etc.	Hello {{name}}! → <'template'>.render (name = "Salman Khan") → Hello Salman Khan!
{%...%}	It is used to create loops and conidtional blocks, i.e., for logics in Jinja2 templates..	It is used when we have control structures, loops or conditional blocks (if-elif-else)	{% for item in list %}
{# ... #}	It is used to add comments in the Jinja2 template.	It is used when we want to add notes or comments in templates for readers to understand code easily.	{# This is a comment #}

Parameter	Functions/ Macros	Template Inheritance
Purpose	Reuse a block of code repeatedly.	Reuse a layout or structure across multiple pages.
Execution	Called when needed	Automatically applied through inheritance
Analogy	Like a utility in a module, called when required.	Like a parent class, that child class extends
Customization	Pass arguements to call it	Overrides blocks to customize content

Character	Key to escape	Purpose
<	& lt;	Less than symbol
>	& gt;	Greater than symbol
&	& amp;	Ampersand
"	& quot;	Double Quotation mark
'	& #39;	Single Quotation Mark

Errors	Causes	How to fix them?
TemplateNotFound Error	Occurs when the template file path is incorrect or the template is missing.	Fix:Ensure the template exists in the correct folder and the file path is accurate.
UndefinedError	This happens when a variable used in the template isn't passed from Python.	Always pass required variables using template.render()and use {{ variable \| default('value') }} for fallbacks.
Improper Use of Control Structures	Forgetting to close blocks like {% if %} or {% for %}	Always close blocks with {% endif %} or {% endfor %}
HTML Injection (XSS) Vulnerability	Directly rendering user input can make your website vulnerable to attacks.	Jinja2 autoescapes by default, but always validate and sanitize user inputs.
Incorrect Filter Usage:	Using non-existent filters or incorrect syntax.	Refer to the Official Jinja2 Filter Documentation for proper usage.

Demystifying Jinja2: The Art of Python Templating

-IMF J050

→ Introduction

→ Contents:

Pre-Requisite Resources:

Jinja2 Essentials:

Security & Best Practices:

Advanced Jinja2 Techniques:

Supporting Tools & Downloads:

Additional Resources:

Thank You