Replace a string in a list of files

#!/usr/bin/python
import fileinput, glob, string, sys, os
from os.path import join
# replace a string in multiple files
#filesearch.py


if len(sys.argv) < 2:
    print "usage: %s search_text replace_text directory" % os.path.basename(sys.argv[0])
    sys.exit(0)


stext = sys.argv[1]
rtext = sys.argv[2]
if len(sys.argv) ==4:
    path = join(sys.argv[3],"*")
else:
    path = "*"


print "finding: " + stext + " replacing with: " + rtext + " in: " + path


files = [filename for filename in os.listdir(".") if not os.path.isdir(filename) and (filename[-4:] == ".cpp" or filename[-2:] == ".h")  ]#glob.glob(path)
print files
for line in fileinput.input(files,inplace=1):
  lineno = 0
  lineno = string.find(line, stext)
  if lineno >0:
        line =line.replace(stext, rtext)