Python 使用 Requests 與 BeautifulSoup 截取並分析網頁內容

範例參考：
A Simple Web Bot with Requests and BeautifulSoup – Stefan Scherfke

函式庫文件：
Requests: HTTP for Humans — Requests 2.3.0 documentation
Beautiful Soup Documentation — Beautiful Soup 4.2.0 documentation

BeautifulSoup find children node

soup.find('li').findAll('a')

Refernces :
python - How to find children of nodes using Beautiful Soup - Stack Overflow 

BeautifulSoup get a link

for link in soup.findAll('a'):
    print link['href']

References :
python/beautifulsoup to find all with specific anchor text - Stack Overflow