通過搜尋字母表的每個字母，然後遍歷json響應的結果頁面，來抓取所有國家資訊。其產生結果將會儲存在表格當中。

import string
from downloader import Downloader
import json
D = Downloader()
template_url = 'http://example.webscraping.com/ajax/search.json?page={}&page_size=10&search_term={}'
countries = set()

for letter in string.lowercase:
    page = 0
 
while True:
        html = D(template_url.format(page, letter))
        try:
            ajax = json.loads(html)#將json格式的資料解析成一個字典
        except ValueError as e:
            print e
            ajax = None
else:
            for record in ajax['records']:
                countries.add(record['country'
 
])
        page += 1
if ajax is None or page >= ajax['num_pages']:
            break
open('countries.txt', 'w').write('\n'.join(sorted(countries)))