从512个字符的数据包中打印出确切的字符数

Question

我正试图弄清楚如何打印出3000个字符。我设法打印了2560，但我不确定如何打印512个字符的数据包。

import urllib
url = raw_input('Enter an URL: ')
try:
data = urllib.urlopen(url)
size = 0
except:
print ('An improperly formatted or non-existent URL')
exit()

while True:
info = data.read(512)
if len(info)<1: break
size = size + len(info)
if size >= 3100: break
print info[0:3000]

Answer 1

import urllib
url = raw_input('Enter an URL: ')
info = ""
try:
data = urllib.urlopen(url)
size = 0
except:
print ('An improperly formatted or non-existent URL')
exit()

while True:
info = info + data.read(512) #read 512 data package
if len(info)<1: break     
if len(info) >= 3000: break  
print len(info[:3000])