Use writelines()
e.g.
# read lines in a file
import sys
arg1 = sys.argv[1]f = open(arg1, 'r')
lines = f.readlines()
f.close()arg='out_'+arg1
FILE=open(arg,'w')for line in lines:
words = line.split(' ')
if words[1] == 'hypnos':
FILE.writelines(line)
FILE.close()
