How many times do you need to do this? You have a list of things to output. The list can be empty, has one element, or more. You want to separate each items with a separator for readability. What do you do? 1. The simple but not reader friendly way:
toppings = [ 'cheese','tomatos','pineapple' ] or toppings = ['cheese']
{% for t in toppings %} {{ t }} , {% endfor %}
that will output: cheese, tomatos, pineapple, or
cheese,
Note the ugly trailing comma.
2. This is the smart way using the template variables available in loops:
{% for t in toppings %} {% if not forloop.first %}, {% endif %} {{ t }} {% endfor %}
that will output: cheese, tomatos, pineapple or
cheese No more trailing commas, thanks to the built in forloop variables.