patrom

patrom is a web templating system, with Python code inserted inside HTML pages.

Templates syntax

The engine uses the custom HTML tag <py>, and a custom HTML attribute attrs.

Code blocks

To insert a code block (loop or condition), the syntax is :

<py code="for i in range(10):">
   ... code block ...
</py>

elif and else keywords must be inserted with their own <py> tag :

<py code="if condition:">
  ...
</py>
<py code="elif condition2:">
  ...
</py>
<py code="else:">
  ...
</py>

break and continue can be used inside loops :

<py code="for i in range(10):">
    <py code="if i == 5:">
        <py code="break" />
    </py>
</py>

Note the use of a self-closing tag (ending with />) for these keywords.

Statements and expressions

For a statement, also use the attribute code inside a self-closing tag:

<py code="x = 5" />

To insert the result of an expression, use the attribute expr:

<py expr="month" />
<py expr="'red' if condition else 'blue'" />

Tag attributes

To set attributes of other HTML tags, use the attribute attrs holding key / value pairs as in keyword arguments of Python functions :

<input attrs="value=name, id=record_id">

For attributes that don't have values, the value associated with the key must be a boolean ; if it is set to True the attribute is set, if it is False it is ignored :

<option attrs="selected=value==expected">

Including templates

A template can be included inside another one :

<py include="header.tmpl" />

Using the patrom module

Installation

pip install patrom

Rendering templates

import patrom
patrom.render(filename, **kw)

renders the template file at location filename with the keyword arguments kw. The keys in kw are used as the namespace for the template.

For instance, if the template file hello.html is

Hello <py expr="name" /> !

the result of

patrom.render("hello.tmpl", name="World")

is

Hello World !

If a template includes another one, the included template is rendered with the same keys / values.