第一个python实例程序

#!/usr/bin/python2.7

import os
ls = os.linesep

fname = raw_input("fname:");

while True:

if os.path.exists(fname):
print "Error:'%s' already exists" % fname
else:
break

all = []
print "\nEnter lines('.' by itself to quit). \n"

while True:
entry = raw_input('> ')

if entry == '.':
break
else:
all.append(entry)

fobj = open(fname, 'w')
fobj.writelines(['%s%s' % (x, ls) for x in all])
fobj.close()
print 'DONE!'