Jinja2

Jinja2 is a templating engine for Python that enables developers to write templates using Python-like syntax. It processes templates by inserting placeholders and special tags that allow template designers to work with data structures and control flow, then renders the final output document. The tool supports template inheritance and inclusion, macro definition, and HTML autoescaping to guard against cross-site scripting attacks. It can also execute templates in a sandboxed environment for safely rendering untrusted content, and provides AsyncIO support for asynchronous template generation. Templates are compiled to optimized Python code and cached for performance.

Jinja2 was developed by Armin Ronacher and is released under the 3-clause BSD License. The engine offers extensibility through custom filters, tests, functions, and syntax modifications. It includes internationalization support via Babel and provides detailed exception reporting that references the correct line numbers in templates for easier debugging.