Python challenge Level 3

#!/usr/bin/python
import string
fp = open('./3.dat','r')
str = fp.read()

for i in range(len(str)):
    flag = True
    if not str[i].islower():
        continue
    for j in range(3):
        if not str[i+j+1].isupper():
            flag = False;
            break;
    if not flag:
        continue
    if not str[i+4].islower():
        continue

    for j in range(3):
        if not str[i+5+j].isupper():
            flag = False;
            break
    if not flag:
        continue
    if not str[i+8].islower():
        continue
    print str[i+4],

这个办法我自己都觉得笨得不行，还是贴一个简洁的给大家看看

>>> import re
>>> "".join(re.findall('[^A-Z][A-Z]{3}([a-z])[A-Z]{3}[^A-Z]', text))
'linkedlist'