python challenge 1-5

1 、

#!/usr/bin/env python
# coding: utf-8
if __name__ == "__main__":
    print pow(2,38)

2、

#!/usr/bin/env python
# coding: utf-8

def move_str_left_twice(input):
    result = ''
    for i in range(len(input)):
        result = result + chr(ord(input[i]) + 2)
    return result
    

if __name__ == "__main__":
    print move_str_left_twice('map')

3、

#!/usr/bin/env python
# coding: utf-8
def find_rare_chr(input):
    result = {}
    step = 0
    for i in range(len(input)):
        if result.has_key(input[i]):
            result[input[i]] = result[input[i]] + 1
        else:
            result[input[i]] = step
            step = step + 1
            
    return sorted(result.items(), key = lambda d:d[1])
    

if __name__ == "__main__":
    print find_rare_chr("""
   .......
    """)

4、

#!/usr/bin/env python
# coding: utf-8
import re

def find_Upper_around_chr(input):
    for item in re.findall('[a-z]{1}[A-Z]{3}[a-z]{1}[A-Z]{3}[a-z]{1}', input):
        print item[4]

if __name__ == "__main__":
    print find_Upper_around_chr("""
 
    """)

5、

#!/usr/bin/env python
# coding: utf-8

from urllib2 import urlopen

def get_real_url(url_num = '56337'):
    pre_url = 'http://www.pythonchallenge.com/pc/def/linkedlist.php?nothing='
    doc = ''
    try:
        doc = urlopen(pre_url + url_num).read()
        url_num = doc.split(' ')[-1]
        if url_num == '82683':
            url_num = '63579'
        print doc
        get_real_url(url_num)
    except:
        print doc
        return

if __name__ == "__main__":
    get_real_url()