import sys, re
file = open("c:/1.txt", "r")
newfile = open("c:/5.txt", "w")
contents = file.read()
def dashrepl(matchobj):
     return matchobj.group(1)
newfile.write(re.sub(".*?(\{\{(U|u)delh\}\}.*?\{\{(U|u)delf\}\}).*?", dashrepl, contents))
newfile.close();
file.close()