replacingWordsWithTags.ipynb

replacingWordsWithTags.ipynb

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    "# Problem\n",
    "Given a string and a and a collection of annotations, we'd like to replace the annotated words in the string with the tags of the annotation. E.g. given\n",
    "\"Hello I like NLP\" \n",
    "and the annotations\n",
    "```\n",
    "[ {\n",
    "    \"start\":0, end:5, \"tag\":\"FOO\",\n",
    "    },\n",
    "    {\n",
    "    \"start\":13, end:16, \"tag\":\"BAR\",\n",
    "    },\n",
    "    ]\n",
    "```\n",
    "We want to get back \"FOO I like BAR!\" \n",
    "   \n",
    "## Insight\n",
    "Naively replacing words inside the string is hard, because we keep modifying the string length with each replacement. Instead, we can build a copy of the string, iterating over the annotations \n",
    "    "
   ]
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   "cell_type": "code",
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   "source": [
    "S = \"Hello I like NLP!\" \n",
    "Annotations = [ {\n",
    "    \"start\":0, \"end\":5, \"tag\":\"FOO\",\n",
    "    },\n",
    "    {\n",
    "    \"start\":13, \"end\":16, \"tag\":\"BAR\",\n",
    "    },\n",
    "    ]\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [],
   "source": [
    "def replaceStringWithTags(original,annos):\n",
    "    prev= 0\n",
    "    annos.sort(key=lambda x:x[\"start\"]) # Sort the annotations\n",
    "    newString =\"\"\n",
    "    for anno in annos:\n",
    "        newString += original[prev:anno[\"start\"]] + anno[\"tag\"]\n",
    "        prev = anno[\"end\"]\n",
    "    newString += original[prev:]\n",
    "    return newString\n",
    "        \n",
    "    "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'FOO I like BAR!'"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "replaceStringWithTags(S,Annotations)"
   ]
  }
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