ryayoung/templatify

An insultingly simple but joyful to use tool for using string-based jinja2 templates in Python.

Template

The ultimate tool for creating jinja2 string-based templates in Python.

It's painfully simple, and doesn't do anything you don't expect it to.

It's a zero-cost, frictionless abstraction that provides convenience, static type safety, runtime template argument validation, and enforces a consistent, declarative programming style, all in less than 50 lines of code.

pip install templatify

# An efficient jinja2 template renderer
@template
def greet_user(name: str, age: int = 10):
    "Hello, {{ name|upper }}! You are {{ age }} years old."

print(greet_user("John"))

Declarative Nature

Before the reader of your code sees the string you defined, they will know it's a template, and they will know what its dependencies are.

Static Type Safety

Your type checker will enforce the function signature you've defined.

Efficiency

All runtime logic, validation, and template creation happens only at the moment your function is created.

This code will NOT run:

@template
def greet_user(name: str, age: int = 10):
    "Hello, {{ name|upper }}! You are {{ ageeee }} years old."

@template guarantees that the parameters of your function match the variables used in the template, ahead of time. The creation and validation of the jinja2 template happens only once. Even the attribute lookup on Template.render() is done in advance, so your calls to greet_user are as frictionless as possible.

Zero-Overhead Runtime Dependency Safety

@template will dynamically generate a function that matches the signature of the one you provided. It will pass the given arguments directly to the render function of the template that was already created and validated when your function was decorated.

Therefore, @template achieves runtime validation that all variables required by your template must be filled, and it does so without any compute cost after your function is created.

What about indentation?

@template will dedent your docstring for you, and remove a single leading newline character if one is present, before creating the jinja template. If you don't like this feature, or think it should be able to be disabled, please reach out or raise an issue.

@template
def greet_user(name: str, age: int = 10):
    """
    Hello, {{ name|upper }}! You are {{ age }} years old.
        - Indented bullet
    """

print("Docstring (before):\n" + greet_user.__doc__)
print("Template (after):\n" + greet_user("John"))

Output:

Docstring (before):

    Hello, {{ name|upper }}! You are {{ age }} years old.
        - Indented bullet
    
Template (after):
Hello, JOHN! You are 10 years old.
    - Indented bullet