django return only part of string

# Import necessary modules
from django import template

# Register a new template filter
register = template.Library()

# Define the custom filter function
@register.filter(name='truncate_chars')
def truncate_chars(value, max_length):
    # Ensure the input value is a string
    value = str(value)

    # Check if the length of the string is greater than the specified maximum length
    if len(value) > max_length:
        # Truncate the string to the specified maximum length and add ellipsis
        truncated_value = value[:max_length] + '...'
        return truncated_value
    else:
        # If the string is already within the specified maximum length, return the original string
        return value

In your Django template:

<!-- Load the custom filter at the top of your template -->
{% load your_app_name %}

<!-- Use the custom filter in your template -->
{{ your_string_variable|truncate_chars:20 }}

Explanation:

1. Import the necessary modules: Import the template module from the django package.

2. Register a new template filter: Create a Library instance using template.Library() to register a custom template filter.

3. Define the custom filter function: Create a function, truncate_chars, that takes a string (value) and a maximum length (max_length) as parameters. Inside the function:

   • Convert the input value to a string to ensure it's treated as a string.
   • Check if the length of the string is greater than the specified maximum length.
   • If the length exceeds the maximum, truncate the string to the specified length and add an ellipsis.
   • If the length is within the maximum, return the original string.

4. In your Django template:

   • Load the custom filter at the top of your template using {% load your_app_name %}, where your_app_name is the name of the app containing the custom filter.
   • Use the custom filter in your template by applying it to a variable with the syntax {{ your_string_variable|truncate_chars:20 }}, where your_string_variable is the variable containing the string you want to truncate, and 20 is the maximum length.