step is a pure-Python module providing a very simple template engine with
minimum syntax. It supports variable expansion, flow control and embedding of
Python code.
Use pip:
# pip install step-template
or download the package from GitHub and run the install script:
# python setup.py install
A template is a string containing any kind of textual content and a set of directives representing variables, control structures and blocks of Python code.
Variables are enclosed in {{}} and follow the same syntax rules as Python
variables; e.g.:
This is variable x: {{x}}
This is the third item of my_list: {{my_list[2]}}
This is not a variable: \{\{x\}\}
If Template is created with escape=True, all variables are auto-escaped
for HTML, unless given with a leading exclamation mark; e.g. raw x: {{!x}}.
The escape-function can be changed via Template().builtins.
Flow control expressions are written like regular Python control structures,
preceded by the % sign and must be closed by a %end<statement> tag; e.g.:
%if (x > 2):
x is greater than 2
%else:
x is {{x}}
%endif
All text between <% and %> is considered Python code; you can use the
builtin echo() function to output some text from within Python code blocks;
e.g.:
<%
import time
echo("Current timestamp is {}".format(time.time()))
%>
<\% This is not Python code %\>
You can use the special function isdef() to perform some actions only if a
name is defined in the template namespace; e.g.:
%if isdef("my_var")
my_var is {{my_var}}
%endif
The get() function returns the specified value from template namespace,
or given fallback if name is undefined, defaulting to None; e.g.:
{{get("x")}} {{get("y", 2)}}
The setopt() function allows you to enable options that modify the template
output; the only supported option is 'strip', which removes leading/trailing
whitespace, contiguous whitespace and empty lines and defaults to true; e.g.:
<%setopt("strip", True)%>
The 'strip' option can also be given as a parameter during Template object
creation; e.g.:
tmpl = step.Template(TEMPLATE_STRING, strip=True)
A backslash at the end of a line will suppress the newline character.
Additional postprocessing can be applied on generated content, via
Template(.., postprocess=some callable or an iterable of callables); e.g.:
step.Template("\xff", postprocess=str.encode).expand() == b"\xc3\xbf"
More examples and a detailed description of the module and its classes are available at http://www.kernel-panic.it/programming/step/.
To run the test suite, just run python setup.py test.
Copyright (c) 2012 Daniele Mazzocchio (danix@kernel-panic.it). Several improvements by Erki Suurjaak.
Licensed under the BSD license (see LICENSE.md file).