Python String Templates

The Template class, found in the standard Python string module, is extremely useful. Start with a template string containing keys you want to replace. By default keys start with "$".

>>> import string
>>> thisTmp = string.Template("The $speed $color $thing1")
>>> thisTmp.substitute(speed='quick', color='brown', thing1='fox')
'The quick brown fox'

You can also pass the substitute method a dictionary with key/value pairs for your template:

>>> strDict = {'speed':'slow', 'color':'toupe', 'thing1':'mango'}
>>> thisTmp.substitute(strDict)
'The slow toupe mango'

This makes it easy to insert variable parts in an otherwise fixed string or file. I use it all the time for generating table-based HTML reports.

Create a file like "report.html" with string keys like "$rowValue1" or "$user" in the appropriate places, and have your script read in the contents as a string Template and do the substitutions. This also allows the report layout/appearance to be altered later without touching the script code.