Ups, I have just seen a bug there...
for name in files:
f = open(name, "r+")
content = f.readlines()
content[0:0] = id
content[-1:] = log
has to be
for name in files:
f = open(name, "r+")
content = f.readlines()
content[0:0] = id
content.append(log)
else the last original line will be deleted.
willi