16_Sorting a DataFrame by Custom Values.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 16_Sorting a DataFrame by Custom Values\n",
    "\n",
    "How to sort a Pandas DataFrame by custom values.\n",
    "\n",
    "### Example\n",
    "\n",
    "Suppose you have a weekday column in string format that you want to sort by day of the week, not alphabetically.\n",
    "\n",
    "### Prepare the DataFrame"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>Date</th>\n",
       "      <th>feature_1</th>\n",
       "      <th>feature_2</th>\n",
       "      <th>feature_3</th>\n",
       "      <th>feature_4</th>\n",
       "      <th>categorical_feature</th>\n",
       "      <th>weekday</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>01/02/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>37</td>\n",
       "      <td>0</td>\n",
       "      <td>foo</td>\n",
       "      <td>Wednesday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>02/02/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>168</td>\n",
       "      <td>0</td>\n",
       "      <td>foo</td>\n",
       "      <td>Thursday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>03/02/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>157</td>\n",
       "      <td>0</td>\n",
       "      <td>other</td>\n",
       "      <td>Friday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>04/02/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>720</td>\n",
       "      <td>0</td>\n",
       "      <td>other</td>\n",
       "      <td>Saturday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>05/02/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>721</td>\n",
       "      <td>0</td>\n",
       "      <td>bar</td>\n",
       "      <td>Sunday</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "         Date  feature_1  feature_2  feature_3  feature_4 categorical_feature  \\\n",
       "0  01/02/2017          0          0         37          0                 foo   \n",
       "1  02/02/2017          0          0        168          0                 foo   \n",
       "2  03/02/2017          0          0        157          0               other   \n",
       "3  04/02/2017          0          0        720          0               other   \n",
       "4  05/02/2017          0          0        721          0                 bar   \n",
       "\n",
       "     weekday  \n",
       "0  Wednesday  \n",
       "1   Thursday  \n",
       "2     Friday  \n",
       "3   Saturday  \n",
       "4     Sunday  "
      ]
     },
     "execution_count": 1,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import pandas as pd\n",
    "\n",
    "# Load the example daily time series dataset:\n",
    "df = pd.read_csv(\"./data_etc/timeseries_daily.csv\")\n",
    "\n",
    "df.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Convert the column to `Categorical`, providing the values you want to sort by in the order they should be sorted"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "weekday_order = [\"Monday\", \"Tuesday\", \"Wednesday\", \"Thursday\", \"Friday\", \"Saturday\", \"Sunday\"]\n",
    "df[\"weekday\"] = pd.Categorical(df[\"weekday\"], weekday_order) "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Now when sorting by this column it will sort by the custom order you supplied"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>Date</th>\n",
       "      <th>feature_1</th>\n",
       "      <th>feature_2</th>\n",
       "      <th>feature_3</th>\n",
       "      <th>feature_4</th>\n",
       "      <th>categorical_feature</th>\n",
       "      <th>weekday</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>159</th>\n",
       "      <td>10/07/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>633</td>\n",
       "      <td>1408</td>\n",
       "      <td>0</td>\n",
       "      <td>other</td>\n",
       "      <td>Monday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>215</th>\n",
       "      <td>04/09/2017</td>\n",
       "      <td>272</td>\n",
       "      <td>1080</td>\n",
       "      <td>2085</td>\n",
       "      <td>791</td>\n",
       "      <td>foo</td>\n",
       "      <td>Monday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>33</th>\n",
       "      <td>06/03/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>205</td>\n",
       "      <td>0</td>\n",
       "      <td>other</td>\n",
       "      <td>Monday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>89</th>\n",
       "      <td>01/05/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>1750</td>\n",
       "      <td>0</td>\n",
       "      <td>other</td>\n",
       "      <td>Monday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>173</th>\n",
       "      <td>24/07/2017</td>\n",
       "      <td>222</td>\n",
       "      <td>792</td>\n",
       "      <td>1646</td>\n",
       "      <td>0</td>\n",
       "      <td>foo</td>\n",
       "      <td>Monday</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "           Date  feature_1  feature_2  feature_3  feature_4  \\\n",
       "159  10/07/2017          0        633       1408          0   \n",
       "215  04/09/2017        272       1080       2085        791   \n",
       "33   06/03/2017          0          0        205          0   \n",
       "89   01/05/2017          0          0       1750          0   \n",
       "173  24/07/2017        222        792       1646          0   \n",
       "\n",
       "    categorical_feature weekday  \n",
       "159               other  Monday  \n",
       "215                 foo  Monday  \n",
       "33                other  Monday  \n",
       "89                other  Monday  \n",
       "173                 foo  Monday  "
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.sort_values(by=\"weekday\").head()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>Date</th>\n",
       "      <th>feature_1</th>\n",
       "      <th>feature_2</th>\n",
       "      <th>feature_3</th>\n",
       "      <th>feature_4</th>\n",
       "      <th>categorical_feature</th>\n",
       "      <th>weekday</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>95</th>\n",
       "      <td>07/05/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>1000</td>\n",
       "      <td>0</td>\n",
       "      <td>foo</td>\n",
       "      <td>Sunday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>277</th>\n",
       "      <td>05/11/2017</td>\n",
       "      <td>983</td>\n",
       "      <td>820</td>\n",
       "      <td>2587</td>\n",
       "      <td>430</td>\n",
       "      <td>other</td>\n",
       "      <td>Sunday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>151</th>\n",
       "      <td>02/07/2017</td>\n",
       "      <td>0</td>\n",
       "      <td>0</td>\n",
       "      <td>1592</td>\n",
       "      <td>0</td>\n",
       "      <td>bar</td>\n",
       "      <td>Sunday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>179</th>\n",
       "      <td>30/07/2017</td>\n",
       "      <td>2315</td>\n",
       "      <td>976</td>\n",
       "      <td>2373</td>\n",
       "      <td>1351</td>\n",
       "      <td>other</td>\n",
       "      <td>Sunday</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>319</th>\n",
       "      <td>17/12/2017</td>\n",
       "      <td>576</td>\n",
       "      <td>485</td>\n",
       "      <td>1809</td>\n",
       "      <td>285</td>\n",
       "      <td>other</td>\n",
       "      <td>Sunday</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "           Date  feature_1  feature_2  feature_3  feature_4  \\\n",
       "95   07/05/2017          0          0       1000          0   \n",
       "277  05/11/2017        983        820       2587        430   \n",
       "151  02/07/2017          0          0       1592          0   \n",
       "179  30/07/2017       2315        976       2373       1351   \n",
       "319  17/12/2017        576        485       1809        285   \n",
       "\n",
       "    categorical_feature weekday  \n",
       "95                  foo  Sunday  \n",
       "277               other  Sunday  \n",
       "151                 bar  Sunday  \n",
       "179               other  Sunday  \n",
       "319               other  Sunday  "
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.sort_values(by=\"weekday\").tail()"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.6.4"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}