Open Google Reader's Starred Items Part II
July 9, 2012
The previous entry on retrieving Google Reader’s Starred items had some problems. - Occassionally, it was failing to open a site - There are times that I want to just check how many items that I starred - It wasn’t easy to read
So, I revisited the code and revised it.
Executing a command
I found out that using os.system to execute a command is considered not a good practice.
os.system("open %s -a 'Google Chrome'" % url)
I see that I didn’t even check the result.
To have better control, I use subprocess.call which takes arguments in list.
Here is the code. By the way, I made it as a function for better readability.
def open_in_browser(url):
# open in Chrome
result = subprocess.call(["open", "-a", "Google Chrome", url])
if result != 0:
print "Error opening the item"
return result
If it returns a non-zero value, the function shows an error message and returns.
The items that it fails to open should not be unstarred. Otherwise, it’ll be forgotten forever.
Adding options
It was easy. I just need to use OptionParser.
- ‘-s’ for not to clear stars.
- ‘-b’ for not to open in browser.
parser = OptionParser()
parser.add_option("-s", action="store_true", default=False,
help="not to clear stars")
parser.add_option("-b", action="store_true", default=False,
help="not to open in browser")
(options, args) = parser.parse_args()
With these options, I can just invoke this command with -s and -b for not clearing the stars and not opening in browser, just to show list of starred items in terminal.
Getting a ‘continuation’ param
Google Reader API returns a parameter called ‘continuation.’
By supplying the continuation to subsequent query, they return the following items.
Without it, I had to unstar everything to get other starred items.
Or maybe I could bump up the number of retrieved items to 1000 or something, so that I can get all the items at once. But it sounds very crude, so I decided to use the continuation.
The ‘continuation’ param is included in the result from API call.
It is enclosed in “ns2:continuation” element.
I use regular expression to get the value.
def get_continuation(feed):
pattern = re.compile(r"""ns2:continuation>(.*)<\/ns2:continuation""", re.M)
result = pattern.search(feed.ToString())
if result:
return result.group(1)
else:
False
If I have a ‘continuation,’ that means I have more starred items.
If I don’t, there is no more starred items.
Revised Code
Overall, I changed top-to-bottom-one-long script to bunch of small functions.
#!/usr/bin/env python
import sys
import gdata.service
import subprocess
import getpass
import urllib
import re
from optparse import OptionParser
from gdata.service import BadAuthentication
URL = '/reader/atom/user/-/state/com.google/starred'
SERVICE = gdata.service.GDataService(account_type='GOOGLE',
service='reader',
server='www.google.com',
source='MyReader')
CONFIG = {'email':'YOUR-EMAIL@gmail.com', 'password':'DUMMY'}
def unstar(entry, token):
i = entry.id.text
s = entry.source.extension_attributes['{http://www.google.com/schemas/reader/atom/}stream-id']
ret = SERVICE.Post(urllib.urlencode({
'i':i,
'r':'user/-/state/com.google/starred',
's':s,
'T':token
}),
'/reader/api/0/edit-tag',
converter = lambda x:x,
extra_headers = {'Content-Type':'application/x-www-form-urlencoded'})
print "Unstar result: %s [id: %s]" % (ret, i)
if ret == "OK":
return 1
else:
return 0
def get_continuation(feed):
pattern = re.compile(r"""ns2:continuation>(.*)<\/ns2:continuation""", re.M)
result = pattern.search(feed.ToString())
if result:
return result.group(1)
else:
return False
def password_prompt():
CONFIG['password'] = getpass.getpass('Enter your password for Google Reader: ')
def open_in_browser(url):
# open in Chrome
result = subprocess.call(["open", "-a", "Google Chrome", url])
if result != 0:
print "Error opening the item"
return result
def login():
try:
SERVICE.ClientLogin(CONFIG['email'], CONFIG['password'])
except BadAuthentication:
print "Wrong password!"
sys.exit()
# authenticated token
return SERVICE.Get('/reader/api/0/token',converter=lambda x:x)
# collect starred items
def starred():
# n = number of items to read per query, default is 20
params = {}
entries = []
while True:
query = gdata.service.Query(feed=URL, params=params)
feed = SERVICE.Get(query.ToUri())
cont = get_continuation(feed)
entries.extend(feed.entry)
if cont:
params['c'] = cont
else:
break
print '*' * len(entries)
return entries
# process starred items
def process_starred(token, entries, options):
total = len(entries)
cleared = 0
for entry in entries:
url = entry.GetHtmlLink().href
print entry.title.text
print url
if options.b != True:
result = open_in_browser(url)
else:
# -b is set, always return 0
result = 0
if options.s != True and result == 0:
# now unstar it
cleared += unstar(entry, token)
print "==============================================================="
return (total, cleared)
def main(options):
password_prompt()
token = login()
entries = starred()
(total, cleared) = process_starred(token, entries, options)
print "%d starred item(s) found and %d cleared" % (total, cleared)
if __name__ == '__main__':
parser = OptionParser()
parser.add_option("-s", action="store_true", default=False,
help="not to clear stars")
parser.add_option("-b", action="store_true", default=False,
help="not to open in browser")
(options, args) = parser.parse_args()
main(options)