[docs] [issue19824] string.Template: Add PHP-style variable expansion example

[anatoly techtonik]

anatoly techtonik added the comment:

There is nothing to add to the class itself. It is about expanding docs section with helpful examples. `string.Template` is undervalued, because it is hard to see how it can be more useful than standard string formatting functions. But for people coming from PHP world, this can be a good start. The docs just need an entrypoint that shows how to use locally defined variables in template string. PHP does this for strings automatically.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue19824>
_______________________________________