Django follows the MVC (Model = database-logic,  View=business-logic  Controller=presentation logic ). We can write the required logics based on programming[python] syntax in models and views but, when we want to write simple logics we should follow the django's template syntax, because programming[python]  syntax is not allowed.

We have the Template syntax as follows:

Syntax	Explanation	Example
{{  variable name   }}	To display the variable value. Just like  " print " as in python	input:
Welcome  "{{ request.user.username }}"
output:
Welcome  "Abhi Ram"
 
{% if  condition %}
     --- logic ----
{% endif  %}	
It is a conditional expression same as " if " condition in python 

input:
{% if request.user.can_edit %}
    <button> Edit </button>
{% endif %}
output: 
if user has attribute "can_edit"  as True then it will give result 
 " <button> Edit </button> "
nothing otherwise.
 
{% if  condition1 %}
    --logic--
{% elif  condition2 %}
    -- logic--
{% else %}
   -- logic --
{% endif %}
 	same as python's   " if...elif....else " 	just like above 
{% for  iterable object %}
   --logic--
{% endfor %}	takes an iterable object  returns an iterator object in every iteration.
To get reverse indexes use " forloop.revcounter "	input:  users = ["Naveen", "Ramu", "Danny", "Shera"]
{% for user in users %}
    {% if forloop.first %} First iter {% endif%} 
    {{ forloop.counter }} . {{ user }}
     {% if forloop.last %} Last iter {% endif%} 
{% endfor %}
output:
    First iter
    1. Naveen
    2. Ramu
    3. Danny
    4. Shera
    Last iter
{% with  author_books = request.user|getbooks %}
      -- logic --
{% endwith %}	access the variable within the block. it's used when we require the same varialbe multiple times	-
{% include 'sub_template.html'  with context=context  %}
                     or
{% include 'menu.html'  %}	This will include the partial tempate data by rendering it with the context	-
{% load library %}	This will load the given library and made its functionality(tags) available in the template	-
{% load tag from library %}	This will load a specific tag from the given library	-
{% url "namespace:name" var1=1 va2=2 %}	This will generate the url by taking  app namespace , view name and required data	-
{% autoescape on|off %}
  {{ data }}
{% endautoescape %}	
It will stop the XSS vulnerabilities  from the script.

-
{% now %}	This gives current datetime and timezone	Todays date: {% now "f" %}
{{ "Hello world"|lower  }}	To convert the text to lowercase 	
{{ "Hello world"|lower  }}  gives  "hello world"

{{ "Hello world"|upper  }}	To convert the text to uppercase	{{ "Hello world"|upper  }}  gives  "HELLO WORLD"
{{ "hyderabad"|capfirst  }}	To convert the first letter to uppercase	{{ "hyderabad"|capfirst  }} gives  "Hyderabad"
{{ "hellow world"|title }}	converts the text to title case	{{ "hellow world"|title }}  gives "Hello World"
{{ "hello    world "|slugify }}	converts given text to slug form	{{ "hello    world "|slugify }}  gives "hello-world"
{{ "this is micropyramid world"|wordcount }}	counts the number of words in the text 	
{{ "this is micropyramid world"|wordcount }}  gives "4"
{{  "this is micropyramid world"|truncatechars: n}}	show's characters up to number "n"	{{  "this is micropyramid"|truncatechars: 7}}  gives "this is ..."
{{  "this is micropyramid world"|truncatewords: n}}	show's words up to number "n"	{{  "this is micropyramid"|truncatechars: 2}}  gives "this is ..."
{{  query_set|length }}	returns the no of objects in quesry set	-
{{ query_set|slice:"start:end"  }}	returns the sliced query set	
{{ query_set|slice:"3:5"  }} same as  "query_set[3:5]"
{{ query_set||dictsort:"key"}}	sort's the query_set based on the given key 	-
{{ query_set|dictsortreversed:"key"}}	sort's the query_set based on the given key  in reversed order	-
{{ var_name|default:"Not assigned"}}	if variable is not provided then default value is replaced	-
{{ datetime_object|date:"d-m-yy"}}	return the date in a given format	-

Same usages as in views:
     Operators: == ,  = ,  > , >= ,  < , <=,
Keywords:   and , or ,  not