pandas.ipynb

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   "source": [
    "### QuickHow\n",
    "Given a pandas dataframe containing a pandas series/column of tuples B, \n",
    "we want to extract B into B1 and B2 and assign them into separate pandas series"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandas as pd\n",
    "import time "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Method 1: (faster)\n",
    "\n",
    "- use pd.Series.tolist() method to return a list of tuples \n",
    "\n",
    "- use pd.DataFrame on the resulting list to turn it into a new pd.DataFrame object, while specifying the original df index\n",
    "\n",
    "- add to the original df "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Original Dataset\n",
      "   A       B\n",
      "0  1  (1, 2)\n",
      "1  2  (3, 4)\n",
      "Method 1\n",
      "Time elapsed :0.005747556686401367\n",
      "   A       B  B1  B2\n",
      "0  1  (1, 2)   1   2\n",
      "1  2  (3, 4)   3   4\n"
     ]
    }
   ],
   "source": [
    "df = pd.DataFrame({'A':[1,2], 'B':[(1,2), (3,4)]})  \n",
    "\n",
    "print(\"Original Dataset\")\n",
    "print(df)\n",
    "\n",
    "start = time.time()\n",
    "df[['B1','B2']] = pd.DataFrame(df['B'].tolist(),index=df.index)\n",
    "print(\"Method 1\")\n",
    "print(\"Time elapsed :\" + str(time.time()-start))\n",
    "print(df)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Method 2: (more Pythonic but much slower for larger dataframes)\n",
    "\n",
    "- use the pd.DataFram.apply method to the column with the pd.Series function"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Method 2\n",
      "Time elapsed :0.0069963932037353516\n",
      "   A       B  B1  B2\n",
      "0  1  (1, 2)   1   2\n",
      "1  2  (3, 4)   3   4\n"
     ]
    }
   ],
   "source": [
    "start = time.time()\n",
    "df[['B1','B2']] = df['B'].apply(pd.Series)\n",
    "print(\"Method 2\")\n",
    "print(\"Time elapsed :\" + str(time.time()-start))\n",
    "print(df)"
   ]
  }
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