gistfile1.py

def get_ASIN(self, ean_13):
    # Set request URL and URL params
    base_url = "http://ecs.amazonaws.com/onca/xml"
    url_params = dict(
        Service='AWSECommerceService',
        Operation='ItemLookup',
        IdType='EAN',
        ItemId=ean_13,
        SearchIndex='Music',
        AWSAccessKeyId=AWS_ACCESS_KEY_ID,
        ResponseGroup='Images,ItemAttributes,EditorialReview,SalesRank')

    url_params['Timestamp'] = time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())
    # Sort params in byte-order
    keys = url_params.keys()
    keys.sort()
    values = map(url_params.get, keys)
    # URL encode the params and values
    url_string = urllib.urlencode(zip(keys,values))
    string_to_sign = "GET\necs.amazonaws.com\n/onca/xml\n%s" % url_string

    # Sign the request with SHA256 and your AWS secret key
    signature = hmac.new(
        key=AWS_SECRET_ACCESS_KEY,
        msg=string_to_sign,
        digestmod=hashlib.sha256).digest()
    # Base64 encode the signature
    signature = base64.encodestring(signature).strip()

    # Make the signature URL safe
    urlencoded_signature = urllib.quote_plus(signature)
    url_string += "&Signature=%s" % urlencoded_signature

    url = "%s?%s" % (base_url, url_string)
    print url
    req = urllib2.Request(url)
    response = urllib2.urlopen(req)
    the_page = response.read()
    
    dom = minidom.parseString(the_page)
    the_asin = dom.getElementsByTagName('ASIN')[0].childNodes[0].data
    self.artist = dom.getElementsByTagName('Artist')[0].childNodes[0].data
    self.title = dom.getElementsByTagName('Title')[0].childNodes[0].data
    return the_asin