Python string templates using the % template operator
Python has an excellent built-in template system -- the % operator. Granted this is not what many people would consider a "real" template system, but it's much more powerful than most people give it credit for.
The key is to combine % with the locals() function. Template code practically writes itself. Remember string templates can have more than just %d and %s style replacements. It can also take a dictionary, like %(DICT_KEY1)s or %(DICT_KEY2)d. Next remember that the locals() function returns a dictionary of local variables. This makes it trivial to merge local variables into a string template.
TEMPLATE="""From: %(FROM)s To: %(TO)s Subject: %(SUBJECT)s Hello %(USERNAME)s, Your account is over quota. Your quota limit is %(LIMIT)d bytes. Your amount used is %(USED)d bytes. """ def format_alert_email (USERNAME, FROM, TO, SUBJECT, LIMIT, USED): return TEMPLATE % locals()
Running the template will give the following results:
>>> print format_alert_email('Joe Bloe','email@example.com','firstname.lastname@example.org','over quota',1000,1234) From: email@example.com To: firstname.lastname@example.org Subject: over quota Hello Joe Bloe, Your account is over quota. Your quota limit is 1000 bytes. Your amount used is 1234 bytes. >>>