import re
filename = "index.html"
newContent = "Hello Python World"
filehandle = open(filename, "r")
data = filehandle.read()
filehandle.close()
matching = re.subn("test", newContent, data)
if matching[1] == 0:
raise "Error while parsing HTML template"
print "Content-Type: text/html\n\n"
print matching[0]