How to check if a url is indexed by google using Google Custom search API and Python?

i need to check if some URLs are indexed by google using a python script and google custom search. I'd like to obtain in the script the same results i obtain when from my browser i google for site:www.example.it. My code is:

import urllib2
import json
import pprint
data = urllib2.urlopen('https://www.googleapis.com/customsearch/v1?key=AIzaSyA3xNw1doOc4rjoUGc7sq1gltQvOgalHqA&cx=017576662512468239146:omuauf_lfve&q=site:http://www.repubblica.it/politica/2014/04/07/news/governo_e_patto_su_italicum_brunetta_a_renzi_riforma_elettorale_entro_pasqua_o_si_dimetta-82947958/?ref=HREA-1')
data=json.load(data)
print data

The output of this is:

{   u'kind': u'customsearch#search',
u'queries': {   u'request': [   {   u'count': 10,
                                    u'cx': u'017576662512468239146:omuauf_lfve',
                                    u'inputEncoding': u'utf8',
                                    u'outputEncoding': u'utf8',
                                    u'safe': u'off',
                                    u'searchTerms': u'site:http://www.repubblica.it/politica/2014/04/07/news/governo_e_patto_su_italicum_brunetta_a_renzi_riforma_elettorale_entro_pasqua_o_si_dimetta-82947958/?ref=HREA-1',
                                    u'title': u'Google Custom Search - site:http://www.repubblica.it/politica/2014/04/07/news/governo_e_patto_su_italicum_brunetta_a_renzi_riforma_elettorale_entro_pasqua_o_si_dimetta-82947958/?ref=HREA-1',
                                    u'totalResults': u'0'}]},
u'searchInformation': {   u'formattedSearchTime': u'0.55',
                          u'formattedTotalResults': u'0',
                          u'searchTime': 0.552849,
                          u'totalResults': u'0'},
u'url': {   u'template': u'https://www.googleapis.com/customsearch/v1?q={searchTerms}&num={count?}&start={startIndex?}&lr={language?}&safe={safe?}&cx={cx?}&cref={cref?}&sort={sort?}&filter={filter?}&gl={gl?}&cr={cr?}&googlehost={googleHost?}&c2coff={disableCnTwTranslation?}&hq={hq?}&hl={hl?}&siteSearch={siteSearch?}&siteSearchFilter={siteSearchFilter?}&exactTerms={exactTerms?}&excludeTerms={excludeTerms?}&linkSite={linkSite?}&orTerms={orTerms?}&relatedSite={relatedSite?}&dateRestrict={dateRestrict?}&lowRange={lowRange?}&highRange={highRange?}&searchType={searchType}&fileType={fileType?}&rights={rights?}&imgSize={imgSize?}&imgType={imgType?}&imgColorType={imgColorType?}&imgDominantColor={imgDominantColor?}&alt=json',
            u'type': u'application/json'}}

As you can see there are no "items" while if you google for site:http://www.repubblica.it/politica/2014/04/07/news/governo_e_patto_su_italicum_brunetta_a_renzi_riforma_elettorale_entro_pasqua_o_si_dimetta-82947958/?ref=HREA-1 you have at least one item.

After various experiments it seems that google custom search doesn't work for the queries site:website.

Do you know any solution or alternative to this problem? Thanks.

With Google CSE you specify the site via your CSE configuration (corresponding to your 'cx' parameter) not via the 'site:' query parameter. In the 'basics' tab of your CSE you should see a section called "Sites to search".