Loading AI tools
Web template engine for Python From Wikipedia, the free encyclopedia
Jinja is a web template engine for the Python programming language. It was created by Armin Ronacher and is licensed under a BSD License. Jinja is similar to the Django template engine, but provides Python-like expressions while ensuring that the templates are evaluated in a sandbox. It is a text-based template language and thus can be used to generate any markup as well as source code.
| |
| Original author(s) | Armin Ronacher |
|---|---|
| Initial release | July 17, 2008[1] |
| Stable release | |
| Repository | |
| Written in | Python |
| Type | Template engine |
| License | BSD License |
| Website | palletsprojects |
The Jinja template engine allows customization of tags,[3] filters (for formatting or transforming values[4]), tests (for evaluating conditions[4]), and globals.[5] Also, unlike the Django template engine, Jinja allows the template designer to call functions with arguments on objects. Jinja is Flask's default template engine [6] and it is also used by Ansible,[7] Trac, and Salt.[8] It is also used to make SQL macros, for example for use with dbt.[9]
Some of the features of Jinja are:[10]
Jinja, like Smarty, also ships with an easy-to-use filter system similar to the Unix pipeline.
The syntax for printing output in Jinja is using the double curly braces, for example {{ Hello, World! }}.
Statements which set variables in jinja or those which do not have an output can be wrapped within {% and %}, using the set keyword. For example {% set foo = 42 %} sets a variable called foo with a value of 42.
Similar to above, comments in jinja can be written using a number sign (#) instead of a percentage (%), for example, {# helpful comment #}.
The syntax for creating a filter in Jinja is a vertical bar (|), for example {{ variable|filter }}. A variable can have multiple filters, for example {{ variable|filter|filter }}).[4]
The syntax for creating a test in Jinja is the keyword is as well as the conditions for evaluating the validity of a test, such as for example {% if variable is divisibleby 10 %}do something{% endif %}).[4]
For loops can be used to iterate over sequences, while retaining their object properties. The following example demonstrates iterating over a list of users with username and password fields.
{% for user in users %}
{{ user.username }}
{{ user.password }}
{% endfor %}
Although break and continue are not allowed inside loops, sequences can be filtered.
Here is a small example of a template file example.html.jinja:[11]
<!DOCTYPE html>
<html>
<head>
<title>{{ variable|escape }}</title>
</head>
<body>
{%- for item in item_list %}
{{ item }}{% if not loop.last %},{% endif %}
{%- endfor %}
</body>
</html>
and templating code:
from jinja2 import Template
with open('example.html.jinja') as f:
tmpl = Template(f.read())
print(tmpl.render(
variable = 'Value with <unsafe> data',
item_list = [1, 2, 3, 4, 5, 6]
))
This produces the HTML string:
<!DOCTYPE html>
<html>
<head>
<title>Value with <unsafe> data</title>
</head>
<body>
1,
2,
3,
4,
5,
6
</body>
</html>
Note the minus sign (-) after the tag {%: If you add a minus sign (-) to the start or end of a block (e.g. a For tag), a comment, or a variable expression, the whitespaces before or after that block will be removed.[12]
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.
