regular expression question

[snacktime]

The primary question is how do I perform a match when the regular
expression contains string variables?  For example, in the following
code I want to match a line that starts with STX, then has any number
of characters, then ends with STX.
Example 2 I'm pretty sure works as I expect, but I'm not sure about
Example 1, and I'm pretty sure about example 3.

import re
from curses.ascii import STX,ETX,FS
STX =  chr(STX)
ETX =  chr(ETX)
FS =  chr(FS)
data = STX + "ONE" + FS + "TWO" + FS + "THREE" + ETX
match = STX + '(.*)' + ETX

# Example 1
# This appears to work, but I'm not sure if the '+' is being used in
the regular expression, or if it's just joining STX, '(.*)', and ETX.

if re.search(STX + '(.*)' + ETX,data):
  print "Matches"

# Example 2
# This also appears to work
if re.search(match,data):
  print "Matches"

# Example 3
# Doesn't work, as STX and ETX are evaluated as the literal strings
'STX' and 'ETX'
if re.search('STX(.*)ETX', data):
  print "Matches"

Chris