Lazy stats

lazy_stats.ipynb

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      "0\n",
      "1\n",
      "2\n",
      "3\n",
      "4\n",
      "5\n",
      "6\n",
      "7\n",
      "8\n",
      "9\n"
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     "data": {
      "text/plain": [
       "{'sum': 45}"
      ]
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   "source": [
    "class Stats:\n",
    "    def __init__(self):\n",
    "        self.processors = {}\n",
    "    \n",
    "    def __call__(self, name):\n",
    "        def wrapper(fn):\n",
    "            self.processors[name] = fn\n",
    "            return fn\n",
    "        return wrapper\n",
    "\n",
    "    def run(self, iterable):\n",
    "        running = {}\n",
    "        \n",
    "        for fn in self.processors.values():\n",
    "            running[fn] = gen = fn()\n",
    "            gen.send(None)\n",
    "        \n",
    "        for x in iterable:\n",
    "            for gen in running.values():\n",
    "                gen.send(x)\n",
    "        \n",
    "        results = {}\n",
    "        for name, fn in self.processors.items():\n",
    "            try:\n",
    "                running[fn].throw(StopIteration)\n",
    "            except StopIteration as e:\n",
    "                res = e.value\n",
    "                results[name] = res\n",
    "        return results\n",
    "            \n",
    "stats = Stats()      \n",
    "    \n",
    "\n",
    "@stats('sum')\n",
    "def sumer():\n",
    "    res = 0\n",
    "    try:    \n",
    "        while True:\n",
    "            x = yield\n",
    "            res += x\n",
    "            print(x)\n",
    "    finally:\n",
    "        return res\n",
    "        \n",
    "\n",
    "\n",
    "stats.run(range(10))"
   ]
  }
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