string_template.py

#!/usr/bin/env python

import string

values = {'var': 'foo'}

t = string.Template("""
Variable        : $var
Escape          : $$
Variable in text: ${var}iable
""")

print 'TEMPLATE:', t.substitute(values)

s = """
Variable        :   %(var)s
Escape          :   %%
Variable in text:   %(var)siable
"""

print 'INTERPOLATION:', s % values