Pystache

Warnings

• breaking Pystache 0.5.0 introduced significant API changes, including the removal of the `View` class and replacement of the `Template` class with `Renderer`. Code written for pre-0.5.0 versions will require updates.
  Fix: Migrate from `View` to plain Python objects or `TemplateSpec` with `Renderer`. Adjust template rendering calls to use `pystache.render()` or `Renderer` instances.
• gotcha The default HTML escape function behaves differently between Python 2 (not escaping single quotes with `cgi.escape()`) and Python 3 (escaping single quotes with `html.escape()`). This can lead to subtle rendering differences or unexpected security issues if not accounted for.
  Fix: Explicitly set a custom escape function via `Renderer(escape=my_escape_func)` if consistent escaping behavior, especially for single quotes, is critical across Python versions.
• gotcha Pystache internally uses unicode. When passing byte strings as input (e.g., from files or network), explicit encoding attributes (`file_encoding`, `string_encoding`, `decode_errors`) on the `Renderer` might be necessary to control conversion and prevent `UnicodeDecodeError` or incorrect rendering.
  Fix: Configure `Renderer` with appropriate `file_encoding`, `string_encoding`, and `decode_errors` parameters, or ensure all template inputs are explicitly unicode strings (Python 3 `str`).
• gotcha If installing from source, Pystache's original code was written for Python 2 and must be converted (e.g., by `2to3`) for Python 3 environments. Importing directly from an unconverted Python 2 source directory in a Python 3 environment will result in a `SyntaxError`.
  Fix: Always install via `pip` which handles the conversion automatically, or ensure manual `2to3` conversion if importing from a source checkout.
• gotcha The `{{.}}` tag (implicit iterator) is supported for accessing the current value within a section context (e.g., when iterating over a list of simple values). While useful, its behavior is not always intuitive and was a later addition to the Mustache spec.
  Fix: Understand the Mustache spec's definition of implicit iterators. Use `{{.}}` primarily within sections iterating over primitive values where you want to render the value itself. For objects, refer to specific properties (e.g., `{{name}}`).

Install

• pip install pystache Install stable version

Imports

• render

  import pystache
  pystache.render(template, context)

• Renderer

  from pystache import Renderer
  renderer = Renderer()

• TemplateSpec

  from pystache.template_spec import TemplateSpec

  Used for advanced customization of template loading on a per-view basis.
• View
  The 'View' class was removed in Pystache 0.5.0; use plain Python objects or 'TemplateSpec' with 'Renderer' instead.

Quickstart

This quickstart demonstrates the basic usage of Pystache with direct rendering, using the Renderer class for more control, and integrating with a simple Python object as a 'view' for data.

import pystache

# Simplest rendering
template = "Hello, {{person}}!"
context = {"person": "World"}
print(pystache.render(template, context))

# Using Renderer for more control (e.g., custom template directories)
renderer = pystache.Renderer()
print(renderer.render(template, context))

# Using a dedicated view class (no inheritance needed since 0.5.0)
class SayHello:
    def to(self):
        return "Pizza"

hello_view = SayHello()
template_view = "Hello, {{to}}!"
print(renderer.render(template_view, hello_view))