在Raspberry Pi中读取URL

Question

I want to read data present in a URL. For example if I had this URL:

http://robolab.in/home-automation.html#ON

I want to read the status 'ON', leaving behind the rest of the URL. How can this be done?

Answer 1

what you are trying to do is called web scraping. In python using urllib/urllib2 library you can achieve this goal.

import urllib

try:
    html=urllib.urlopen('http://robolab.in/home-automation.html#ON')
    htmltext=html.read()
except:
    print 'error opening link'

print htmltext

this prints the html text that your browser shows you. now this is just a string... you can manipulate it anyway you want. But if you have BeautifulSoup installed you can code something like this:

from bs4 import BeautifulSoup

soup=BeautifulSoup(htmltext)
for script in soup(["script", "style"]):
    script.extract()
text = soup.get_text()
print text

using this code and given your url I got this:

Robolab Technologies
Home Automation

OFF

and you can easily proceed

status=''
text=text.strip()
for index,line in enumerate(text):
    if index>3:
        status = line
if 'ON' in status:
    print "it's on"
else:
    print "it's off"