[Google App Engine][Python]Amazon Product Advertising API browsenodelookupを追加

ちょこちょこ修正を加えているAmazon Product Advertising APIを検索するPythonコードですが、以下のような形でbrowsenodelookupを検索するコードを追加しました。

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

from urlparse import urlparse
from google.appengine.api import urlfetch
from lxml import etree

import os
import urllib
import datetime
import hashlib
import base64
import logging
import hmac
import xmltodict

class AmazonProductAdvertisingAPI(object):
  def __init__(self,access_key_id,secret_access_key,associate_tag = None,locale = "US"):

    self._access_key_id = access_key_id
    self._secret_access_key = secret_access_key
    self._associate_tag = associate_tag

    self._validate_certificate = True
    _environ = os.environ
    _http_host = _environ["HTTP_HOST"]
    if _http_host.find("localhost") > -1:
      self._validate_certificate = False

    _wsgi_url_scheme = _environ["wsgi.url_scheme"]
    self._endpoint = {
      "JP":_wsgi_url_scheme + "://webservices.amazon.co.jp/onca/xml",
      "US":_wsgi_url_scheme + "://webservices.amazon.com/onca/xml",
      "FR":_wsgi_url_scheme + "://webservices.amazon.fr/onca/xml",
      "IN":_wsgi_url_scheme + "://webservices.amazon.in/onca/xml",
      "IT":_wsgi_url_scheme + "://webservices.amazon.it/onca/xml",
      "UK":_wsgi_url_scheme + "://webservices.amazon.co.uk/onca/xml"
    }

    if self._endpoint.has_key(locale):
      self._product_advertising_url = self._endpoint[locale]
    else:
      self._product_advertising_url = self._endpoint["US"]

    self._service = "AWSECommerceService"

    #self._method = ""
    #self._prms = {}

  #タイムスタンプを設定
  def _timestamp(self,prms):

    prms["Timestamp"] = datetime.datetime.utcnow().strftime("%Y-%m-%dT%H:%M:%SZ")

  #URLエンコード
  def _urlencode_rfc3986(self,s):
    _s = urllib.quote(s)
    _s = _s.replace("%7E", "~")
    return _s

  #アクセストークン用の文字列作成
  def _canonical_string(self,prms):

    _keys = sorted(prms)
    _canonical_string = ""
    for _k in _keys:
      _canonical_string = _canonical_string + "&" + self._urlencode_rfc3986(_k) + "=" + self._urlencode_rfc3986(prms[_k])
    else:
      _canonical_string = _canonical_string[1:]

    return _canonical_string

  #問い合わせURLの作成
  def _request_url(self,prms,method):

    _url_info = urlparse(self._product_advertising_url)

    _canonical_string = self._canonical_string(prms)

    _signature = method + "\n" + _url_info.hostname + "\n" + _url_info.path +"\n" + _canonical_string
    _signature = hmac.new(self._secret_access_key, _signature, hashlib.sha256).digest()
    _signature = base64.b64encode(_signature)

    _url = self._product_advertising_url + "?" + _canonical_string + "&Signature=" + self._urlencode_rfc3986(_signature)

    return _url

  #itemsearch
  def itemsearch(self,searchindex,browsenode=None,availability="Available",responsegroup="Small",itempage=1,keywords=None,minimumprice=None,maximumprice=None,isremoveadult=True,sort=None):

    _prms = {}

    _prms["Service"] = self._service
    _prms["AWSAccessKeyId"] = self._access_key_id

    if self._associate_tag is not None:
      _prms["AssociateTag"] = self._associate_tag

    _prms["Operation"] = "ItemSearch"
    self._timestamp(_prms)
    
    if availability is None:
      return None

    for i in ["Available"]:
      if i == availability:
        _prms["Availability"] = availability
        break
    else:
      return None

    if searchindex is None:
      return None

    if searchindex == u"":
      return None

    _prms["SearchIndex"] = searchindex

    if responsegroup is None:
      return None

    if responsegroup == "":
      return None

    _prms["ResponseGroup"] = responsegroup

    if browsenode is not None:
      _prms["BrowseNode"] = browsenode

    if itempage is not None:
      _prms["ItemPage"] = str(itempage)

    if keywords is not None:
      #logging.info()
      if isinstance(keywords,unicode):
        #logging.info(keywords)
        _prms["Keywords"] = keywords.encode('utf-8')
      else:
        _prms["Keywords"] = keywords
      #_prms["Keywords"] = keywords

    if maximumprice is not None:
      _prms["MaximumPrice"] = str(maximumprice)

    if minimumprice is not None:
      _prms["MinimumPrice"] = str(minimumprice)

    if sort is not None:
      _prms["Sort"] = sort


    _url = self._request_url(_prms,"GET")
    #logging.info(_url)
    _result = self._request(_url)
    return _result

  #itemlookup
  def itemlookup(self,asin,responsegroup="Small"):
    _prms = {}

    _prms["Service"] = self._service
    _prms["AWSAccessKeyId"] = self._access_key_id

    if self._associate_tag is not None:
      _prms["AssociateTag"] = self._associate_tag

    _prms["Operation"] = "ItemLookup"
    self._timestamp(_prms)

    if asin is None:
      return None

    if asin == "":
      return None

    _prms["ItemId"] = asin

    if responsegroup is None:
      return None

    if responsegroup == "":
      return None

    _prms["ResponseGroup"] = responsegroup

    _url = self._request_url(_prms,"GET")
    _result = self._request(_url)
    return _result

  def _request(self,url):
    try:
      _result = urlfetch.fetch(url,validate_certificate = self._validate_certificate)
      _status_code = _result.status_code
      #logging.info(_status_code)

      if _status_code == 200:

        _content = _result.content
        _root = etree.fromstring(_content)
        _ns = _root.xpath('namespace-uri(.)')
        _namespace = {"ns":_ns}
        _errorTags = _root.findall('.//ns:Error',namespaces=_namespace)
        #logging.info(_content)
        if len(_errorTags) > 0:
          _errorTag = _errorTags[0]
          _code  = _errorTag.findall('.//ns:Code',namespaces=_namespace)
          _message = _errorTag.findall('.//ns:Message',namespaces=_namespace)
          logging.error(u"code: " + _code[0].text + " message: " + _message[0].text)
        else:
          return _root
      else:
        logging.error(u"status code: " + str(_status_code) + " content:" + _content)
        
    except urlfetch.DeadlineExceededError:
      logging.error(u"urlfetch DeadlineExceededError")

    except urlfetch.ResponseTooLargeError, response:
      logging.error(u"urlfetch ResponseTooLargeError" + response)

    except urlfetch.InternalTransientError:
      logging.error(u"urlfetch InternalTransientError")

    except urlfetch.InvalidURLError:
      logging.error(u"urlfetch InvalidURLError")

    except urlfetch.Error:
      logging.error(u"urlfetch Error")

    return None


  def browsenodelookup(self,browsenodeid):

      _prms = {}

      _prms["Service"] = self._service
      _prms["AWSAccessKeyId"] = self._access_key_id

      if browsenodeid is None or browsenodeid == "":
        return None

      if isinstance(browsenodeid,unicode):
        _prms["BrowseNodeId"] = browsenodeid.encode('utf-8')
      else:
        _prms["BrowseNodeId"] = browsenodeid

      if self._associate_tag is not None:
        _prms["AssociateTag"] = self._associate_tag

      _prms["Operation"] = "BrowseNodeLookup"
      self._timestamp(_prms)

      _url = self._request_url(_prms,"GET")
      #logging.info(_url)
      _result = self._request(_url)
      return _result