Full code for achieving highlighted Plotly Express line charts on the background of grey lines

GIST_Highlighted_Line_Chart.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Highlighted line chart"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import plotly.express as px\n",
    "import pandas as pd\n",
    "import numpy as np"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "# then load the preprocessed pickles\n",
    "long_df = pd.read_pickle(\"../Preprocess/long.plk\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "# annotation at the beginning of the line \n",
    "# use the \"xanchor\": \"right\" so that the labels stick to the right side of the plot area\n",
    "# since you use \"xref\": \"paper\", the annotations are stick to canvas and not the plot area, even if you set y in absolute numbers\n",
    "turkey_annotation = \\\n",
    "[{\"xref\": \"paper\", \"x\":0, \"y\":7_000_000,\n",
    "  \"xanchor\":'right', \"yanchor\":\"middle\",\n",
    "  \"text\":'7M',\n",
    "  \"font\":dict(family='Arial', size=15, color=\"red\"),\n",
    "  \"showarrow\":False},\n",
    "  # end of the line legend\n",
    "  # use the \"xanchor\": \"left\" so that the labels stick to the right side of the plot area\n",
    "  {\"xref\":\"paper\", \"x\":1, \"y\":45_000_000,\n",
    "   \"xanchor\":\"left\", \"yanchor\":\"middle\",\n",
    "   \"text\":'Turkey (45M)',\n",
    "   \"font\":dict(family='Arial', size=15, color=\"red\"),\n",
    "   \"showarrow\":False},]\n",
    "\n",
    "japan_annotation = [{\"xref\": \"paper\", \"x\":0, \"y\":3_300_000,\n",
    "                    \"xanchor\":'right', \"yanchor\":'middle',\n",
    "                    \"text\":'3.3M',\n",
    "                    \"font\":dict(family='Arial',\n",
    "                                size=15,\n",
    "                                color=\"blue\"),\n",
    "                    \"showarrow\":False}, \n",
    "                   {\"xref\":\"paper\", \"x\":1, \"y\":31_000_000,\n",
    "                    \"xanchor\":'left', \"yanchor\":'middle',\n",
    "                    \"text\":'Japan (31M)',\n",
    "                    \"font\":dict(family='Arial',\n",
    "                                size=15,\n",
    "                                color=\"blue\"),\n",
    "                    \"showarrow\":False}]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "# add an arrow pointing to interesting point\n",
    "tourism_boom_in_japan_annotation = [{\"x\":2011, \"y\":6220000, \"ay\": -40, \n",
    "                        \"text\": \"<b>Tourism Boom<br> in Japan 2011</b>\",\n",
    "                        \"arrowhead\": 3, \"showarrow\":True,\n",
    "                        \"font\": {\"size\": 15}, \"bgcolor\":None, \"textangle\": 0}]\n",
    "\n",
    "# add the description in the middle of the plot\n",
    "area_annotation =  [{\"x\":2007, \"y\":40000000, \n",
    "                        \"text\": \"<b>Number of tourist is growing</b>\",\n",
    "                         \"textangle\": -25,\n",
    "                        \"showarrow\":False,\n",
    "                         \"bgcolor\":\"lightblue\",\n",
    "                        \"font\": {\"size\": 15}}]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "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>Country Name</th>\n",
       "      <th>Country Code</th>\n",
       "      <th>Region</th>\n",
       "      <th>years</th>\n",
       "      <th>visitors</th>\n",
       "      <th>receipts</th>\n",
       "      <th>order</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>4945</th>\n",
       "      <td>Aruba</td>\n",
       "      <td>ABW</td>\n",
       "      <td>Latin America &amp; Caribbean</td>\n",
       "      <td>2018</td>\n",
       "      <td>1082000.0</td>\n",
       "      <td>2.024000e+09</td>\n",
       "      <td>3.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4946</th>\n",
       "      <td>Afghanistan</td>\n",
       "      <td>AFG</td>\n",
       "      <td>South Asia</td>\n",
       "      <td>2018</td>\n",
       "      <td>0.0</td>\n",
       "      <td>5.000000e+07</td>\n",
       "      <td>3.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4947</th>\n",
       "      <td>Angola</td>\n",
       "      <td>AGO</td>\n",
       "      <td>Sub-Saharan Africa</td>\n",
       "      <td>2018</td>\n",
       "      <td>218000.0</td>\n",
       "      <td>5.570000e+08</td>\n",
       "      <td>3.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     Country Name Country Code                     Region years   visitors  \\\n",
       "4945        Aruba          ABW  Latin America & Caribbean  2018  1082000.0   \n",
       "4946  Afghanistan          AFG                 South Asia  2018        0.0   \n",
       "4947       Angola          AGO         Sub-Saharan Africa  2018   218000.0   \n",
       "\n",
       "          receipts  order  \n",
       "4945  2.024000e+09    3.0  \n",
       "4946  5.000000e+07    3.0  \n",
       "4947  5.570000e+08    3.0  "
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# sort the dataframe\n",
    "sorted_df = long_df.copy()\n",
    "\n",
    "# map the value order\n",
    "sorted_df[\"order\"] = sorted_df[\"Country Name\"].map({\"Japan\": 1, \"Turkey\": 2}).fillna(3)\n",
    "\n",
    "# sort by this order\n",
    "sorted_df.sort_values(by=[\"order\",\"years\"], ascending=False, inplace=True)\n",
    "sorted_df.head(3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fig = px.line(sorted_df,\n",
    "              x=\"years\",\n",
    "              y=\"visitors\", \n",
    "              color=\"Country Name\", \n",
    "              line_group=\"Country Name\")\n",
    "\n",
    "# set color of all traces to lightgrey\n",
    "fig.update_traces({\"line\":{\"color\":\"lightgrey\"}})\n",
    "\n",
    "# color Turkish line to blue\n",
    "fig.update_traces(patch={\"line\":{\"color\":\"blue\", \"width\":5}}, \n",
    "                  selector={\"legendgroup\":\"Turkey\"})\n",
    "\n",
    "# color Japanese line to red\n",
    "fig.update_traces(patch={\"line\":{\"color\":\"red\", \"width\":5}}, \n",
    "                  selector={\"legendgroup\":\"Japan\"})\n",
    "\n",
    "fig.update_layout(title=\"Tourism Growth in Turkey and Japan\",\n",
    "                # remove the legent\n",
    "                showlegend=False,\n",
    "                  \n",
    "                # make y-axis invisible\n",
    "                yaxis={\"visible\":False},\n",
    "                \n",
    "                # create the annoations\n",
    "                # point annotattion\n",
    "                annotations=turkey_annotation+japan_annotation+tourism_boom_in_japan_annotation+area_annotation,\n",
    "                 \n",
    "                # adjust the margin, so that annotations fit into the canvas\n",
    "                margin={\"l\":50, \"r\": 100})\n",
    "fig.show()"
   ]
  }
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