生成随机验证码

import random
a=[]
c =‘‘
for  i in range(6):
    if i == random.randrange(1,4):
        a.append(str(random.randint(1,9)))
    else:
        temp = random.randint(65,90)
        a.append(chr(temp))
print a

b="".join(a)
print b
for i in a:
    c += str(i)
print c

import cStringIO
import StringIO
import time
values = []

items = [‘1,2,31,2,31,2,31,2,3‘] * 10000000
#print items
st = float(time.time())


for i in items:
    values.append(i)
news = ‘‘.join(values)
print len(news)
print ‘list append cost time:%s‘%(float(time.time()) - st)

strio = cStringIO.StringIO()
st = float(time.time())
for j in items:
    strio.write(j)
print len(strio.getvalue())
print ‘cStringIO cost time:%s‘%(float(time.time()) - st)


strio = StringIO.StringIO()
st = float(time.time())
for j in items:
    strio.write(j)
print len(strio.getvalue())
print ‘StringIO cost time:%s‘%(float(time.time()) - st)