String template class with Oracle/SAS-style substitution rules.

gistfile1.py

from string import Template

class OracleTemplate(string.Template):
    """Substitution variables, ala Oracle SQL*Plus"""

    pattern = r"""
        &(?:
          (?P<escaped>&) |
          (?P<braced>[_a-z0-9]+)\. |
          (?P<named>[_a-z0-9]+) |
          (?P<invalid>)
        )
    """
    delimiter = '&'
    idpattern = '[_a-z0-9]+'


# example
t = OracleTemplate("""\
    SELECT
      t.*
    FROM
      &schema..transactions t
    WHERE
      t.state = '&state'
    ;
""")

print t.substitute(schema='prod', state='VIC')