A proxying interface to the Evernote Python SDK as one approach to dealing with rate limiting: simple retry after suggested wait.

Evernote_rate_limit.json

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     "source": [
      "My notes for background to problem -- implementing rate limiting into my use of the Evernote API ( http://dev.evernote.com/doc/articles/rate_limits.php )\n",
      "\n",
      "https://www.evernote.com/shard/s1/sh/5327734c-fdfd-4d1c-9af4-8a32ad7a2e51/2d234b29342f3b8c8c4ec3d180c8861d\n",
      "\n",
      "Basic approach to explore:\n",
      "\n",
      "* proxying the existing EvernoteClient object or client\n",
      "* learning from Python decorators about how to do a retry\n",
      "* down the road, look at using `APScheduler` or `celery` to do more sophisticated handling of asynchronous retries.\n",
      "\n",
      "I was considering using a class decorator: http://my.safaribooksonline.com/book/programming/python/9780768687040/classes-and-object-oriented-programming/ch07lev1sec17"
     ]
    },
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     "input": [
      "import evernote\n",
      "\n",
      "from time import sleep\n",
      "from evernote.edam.error.ttypes import (EDAMSystemException, EDAMErrorCode)\n",
      "\n",
      "def evernote_rate_limit(f):\n",
      "    def f2(*args, **kwargs):\n",
      "        try:\n",
      "            return f(*args, **kwargs)\n",
      "        except EDAMSystemException, e:\n",
      "            if e.errorCode == EDAMErrorCode.RATE_LIMIT_REACHED:\n",
      "                sleep(e.rateLimitDuration)\n",
      "                return f(*args, **kwargs)\n",
      "    \n",
      "    return f2\n",
      "\n",
      "\n",
      "class RateLimitingEvernoteProxy(object):\n",
      "    __slots__ = [\"_obj\"]\n",
      "    def __init__(self, obj):\n",
      "        object.__setattr__(self, \"_obj\", obj)\n",
      "    \n",
      "    def __getattribute__(self, name):\n",
      "        return evernote_rate_limit(getattr(object.__getattribute__(self, \"_obj\"), name))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
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     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# settings holds the devToken/authToken that can be used to access Evernote account\n",
      "#http://dev.evernote.com/doc/articles/authentication.php#devtoken\n",
      "# settings.authToken\n",
      "\n",
      "import settings\n",
      "\n",
      "\n",
      "from evernote.api.client import EvernoteClient\n",
      "\n",
      "dev_token = settings.authToken\n",
      "\n",
      "client = RateLimitingEvernoteProxy(EvernoteClient(token=dev_token, sandbox=False))\n",
      "\n",
      "userStore = client.get_user_store()\n",
      "user = userStore.getUser()\n",
      "print user.username"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "rdhyee\n"
       ]
      }
     ],
     "prompt_number": 2
    },
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     "cell_type": "code",
     "collapsed": false,
     "input": [
      "type(client)"
     ],
     "language": "python",
     "metadata": {},
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       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 3,
       "text": [
        "__main__.RateLimitingEvernoteProxy"
       ]
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