diff --git a/Assignment1/Assignment1.ipynb b/Assignment1/Assignment1.ipynb
index 4df9a60..ca49c32 100644
--- a/Assignment1/Assignment1.ipynb
+++ b/Assignment1/Assignment1.ipynb
@@ -1508,7 +1508,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 122,
+   "execution_count": 194,
    "id": "5d1fad2a",
    "metadata": {},
    "outputs": [
@@ -1541,8 +1541,8 @@
        "      <th>Bosnia and Herzegovina</th>\n",
        "      <th>Bulgaria</th>\n",
        "      <th>Croatia</th>\n",
-       "      <th>Cyprus</th>\n",
        "      <th>Czech Republic</th>\n",
+       "      <th>Denmark</th>\n",
        "      <th>...</th>\n",
        "      <th>San Marino</th>\n",
        "      <th>Serbia</th>\n",
@@ -1583,174 +1583,166 @@
        "  <tbody>\n",
        "    <tr>\n",
        "      <th>Albania</th>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>1</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
        "      <td>...</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>1</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>1</td>\n",
-       "      <td>0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>0.0</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>Andorra</th>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
        "      <td>...</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>Austria</th>\n",
-       "      <td>1</td>\n",
-       "      <td>0</td>\n",
-       "      <td>15</td>\n",
-       "      <td>2</td>\n",
-       "      <td>2</td>\n",
-       "      <td>1</td>\n",
-       "      <td>3</td>\n",
-       "      <td>6</td>\n",
-       "      <td>3</td>\n",
-       "      <td>1</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>15.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>3.0</td>\n",
+       "      <td>6.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>5.0</td>\n",
        "      <td>...</td>\n",
-       "      <td>0</td>\n",
-       "      <td>3</td>\n",
-       "      <td>1</td>\n",
-       "      <td>2</td>\n",
-       "      <td>40</td>\n",
-       "      <td>4</td>\n",
-       "      <td>11</td>\n",
-       "      <td>10</td>\n",
-       "      <td>11</td>\n",
-       "      <td>0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>3.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>40.0</td>\n",
+       "      <td>4.0</td>\n",
+       "      <td>11.0</td>\n",
+       "      <td>10.0</td>\n",
+       "      <td>11.0</td>\n",
+       "      <td>0.0</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>Belarus</th>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>2</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>1</td>\n",
-       "      <td>2</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>0.0</td>\n",
        "      <td>...</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>1</td>\n",
-       "      <td>1</td>\n",
-       "      <td>1</td>\n",
-       "      <td>2</td>\n",
-       "      <td>1</td>\n",
-       "      <td>0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>0.0</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>Belgium</th>\n",
-       "      <td>0</td>\n",
-       "      <td>0</td>\n",
-       "      <td>2</td>\n",
-       "      <td>0</td>\n",
-       "      <td>1</td>\n",
-       "      <td>0</td>\n",
-       "      <td>4</td>\n",
-       "      <td>5</td>\n",
-       "      <td>2</td>\n",
-       "      <td>4</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>4.0</td>\n",
+       "      <td>5.0</td>\n",
+       "      <td>4.0</td>\n",
+       "      <td>5.0</td>\n",
        "      <td>...</td>\n",
-       "      <td>0</td>\n",
-       "      <td>2</td>\n",
-       "      <td>1</td>\n",
-       "      <td>3</td>\n",
-       "      <td>60</td>\n",
-       "      <td>6</td>\n",
-       "      <td>6</td>\n",
-       "      <td>2</td>\n",
-       "      <td>17</td>\n",
-       "      <td>0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>3.0</td>\n",
+       "      <td>60.0</td>\n",
+       "      <td>6.0</td>\n",
+       "      <td>6.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>17.0</td>\n",
+       "      <td>0.0</td>\n",
        "    </tr>\n",
        "  </tbody>\n",
        "</table>\n",
-       "<p>5 rows × 47 columns</p>\n",
+       "<p>5 rows × 46 columns</p>\n",
        "</div>"
       ],
       "text/plain": [
        "country       Albania  Andorra  Austria  Belarus  Belgium  \\\n",
        "country_dest                                                \n",
-       "Albania             0        0        1        0        0   \n",
-       "Andorra             0        0        0        0        0   \n",
-       "Austria             1        0       15        2        2   \n",
-       "Belarus             0        0        2        0        0   \n",
-       "Belgium             0        0        2        0        1   \n",
+       "Albania           0.0      0.0      1.0      0.0      0.0   \n",
+       "Andorra           0.0      0.0      0.0      0.0      0.0   \n",
+       "Austria           1.0      0.0     15.0      2.0      2.0   \n",
+       "Belarus           0.0      0.0      2.0      0.0      0.0   \n",
+       "Belgium           0.0      0.0      2.0      0.0      1.0   \n",
        "\n",
-       "country       Bosnia and Herzegovina  Bulgaria  Croatia  Cyprus  \\\n",
-       "country_dest                                                      \n",
-       "Albania                            0         0        0       0   \n",
-       "Andorra                            0         0        0       0   \n",
-       "Austria                            1         3        6       3   \n",
-       "Belarus                            0         0        0       1   \n",
-       "Belgium                            0         4        5       2   \n",
+       "country       Bosnia and Herzegovina  Bulgaria  Croatia  Czech Republic  \\\n",
+       "country_dest                                                              \n",
+       "Albania                          0.0       0.0      0.0             0.0   \n",
+       "Andorra                          0.0       0.0      0.0             0.0   \n",
+       "Austria                          1.0       3.0      6.0             1.0   \n",
+       "Belarus                          0.0       0.0      0.0             2.0   \n",
+       "Belgium                          0.0       4.0      5.0             4.0   \n",
        "\n",
-       "country       Czech Republic  ...  San Marino  Serbia  Slovakia  Slovenia  \\\n",
-       "country_dest                  ...                                           \n",
-       "Albania                    0  ...           0       0         0         1   \n",
-       "Andorra                    0  ...           0       0         0         0   \n",
-       "Austria                    1  ...           0       3         1         2   \n",
-       "Belarus                    2  ...           0       0         0         0   \n",
-       "Belgium                    4  ...           0       2         1         3   \n",
+       "country       Denmark  ...  San Marino  Serbia  Slovakia  Slovenia  Spain  \\\n",
+       "country_dest           ...                                                  \n",
+       "Albania           0.0  ...         0.0     0.0       0.0       1.0    0.0   \n",
+       "Andorra           0.0  ...         0.0     0.0       0.0       0.0    0.0   \n",
+       "Austria           5.0  ...         0.0     3.0       1.0       2.0   40.0   \n",
+       "Belarus           0.0  ...         0.0     0.0       0.0       0.0    1.0   \n",
+       "Belgium           5.0  ...         0.0     2.0       1.0       3.0   60.0   \n",
        "\n",
-       "country       Spain  Sweden  Switzerland  Ukraine  United Kingdom  \\\n",
-       "country_dest                                                        \n",
-       "Albania           0       0            0        0               1   \n",
-       "Andorra           0       0            0        0               0   \n",
-       "Austria          40       4           11       10              11   \n",
-       "Belarus           1       1            1        2               1   \n",
-       "Belgium          60       6            6        2              17   \n",
+       "country       Sweden  Switzerland  Ukraine  United Kingdom  Vatican City  \n",
+       "country_dest                                                              \n",
+       "Albania          0.0          0.0      0.0             1.0           0.0  \n",
+       "Andorra          0.0          0.0      0.0             0.0           0.0  \n",
+       "Austria          4.0         11.0     10.0            11.0           0.0  \n",
+       "Belarus          1.0          1.0      2.0             1.0           0.0  \n",
+       "Belgium          6.0          6.0      2.0            17.0           0.0  \n",
        "\n",
-       "country       Vatican City  \n",
-       "country_dest                \n",
-       "Albania                  0  \n",
-       "Andorra                  0  \n",
-       "Austria                  0  \n",
-       "Belarus                  0  \n",
-       "Belgium                  0  \n",
-       "\n",
-       "[5 rows x 47 columns]"
+       "[5 rows x 46 columns]"
       ]
      },
-     "execution_count": 122,
+     "execution_count": 194,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1762,7 +1754,9 @@
     "df_routes = pd.read_csv(\"./datasets/routes.csv\", na_values=['\\\\N'], sep=\";\") \\\n",
     "    .rename(lambda x: x.strip(), axis=1)\n",
     "\n",
-    "df_countries = pd.read_csv(\"./datasets/countries.csv\") \\\n",
+    "# Note that I consider a country to be 'European' if the 'continent' country in countries.csv is equal to 'eu' \n",
+    "df_countries = pd.read_csv(\"./datasets/countries.csv\") \n",
+    "df_countries = df_countries.loc[df_countries.continent == 'eu', :] \\\n",
     "    .rename(columns={'name': 'country'}).drop(columns=['continent'])\n",
     "\n",
     "df_countries.loc[df_countries.country == 'Faroe Is.', 'country'] = 'Faroe Islands'\n",
@@ -1779,7 +1773,7 @@
     "    .join(df_id_country, how='right', on='source_airport') \\\n",
     "    .join(df_id_country, how='right', on='destination_airport', rsuffix='_dest')\n",
     "\n",
-    "# Count only a pair of notna source and destination airport as a valid route\n",
+    "# Count only a pair of notna source and destination airport as a valid flight\n",
     "# When this is not a case the row is an artifact of the right join. We assign 0\n",
     "# as a value so that in the final sum the value will still appear to include \n",
     "# no-flight countries, albeit with a total number of routes to 0\n",
@@ -1795,16 +1789,16 @@
     "    .fillna(0) \\\n",
     "    .sort_values('country_dest')\n",
     "\n",
-    "# Change type of cells and remove column level for geopandas compatibility\n",
-    "df_routes_count = df_routes_count[df_routes_count.columns].astype(int)\n",
+    "# Change type of cells to float and remove column level for geopandas compatibility\n",
+    "df_routes_count = df_routes_count[df_routes_count.columns].astype(float)\n",
     "df_routes_count.columns = df_routes_count.columns.droplevel(0)\n",
     "df_routes_count.head()"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 128,
-   "id": "75225ed4",
+   "execution_count": 195,
+   "id": "87bd101d",
    "metadata": {},
    "outputs": [
     {
@@ -1854,30 +1848,6 @@
        "  <tbody>\n",
        "    <tr>\n",
        "      <th>0</th>\n",
-       "      <td>Azerbaijan</td>\n",
-       "      <td>MULTIPOLYGON (((45.08332 39.76804, 45.26639 39...</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>...</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>1</th>\n",
        "      <td>Albania</td>\n",
        "      <td>POLYGON ((19.43621 41.02107, 19.45055 41.06000...</td>\n",
        "      <td>0.0</td>\n",
@@ -1901,31 +1871,7 @@
        "      <td>0.0</td>\n",
        "    </tr>\n",
        "    <tr>\n",
-       "      <th>2</th>\n",
-       "      <td>Armenia</td>\n",
-       "      <td>MULTIPOLYGON (((45.57305 40.63249, 45.52888 40...</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>...</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "      <td>NaN</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>3</th>\n",
+       "      <th>1</th>\n",
        "      <td>Bosnia and Herzegovina</td>\n",
        "      <td>POLYGON ((17.64984 42.88908, 17.57853 42.94382...</td>\n",
        "      <td>0.0</td>\n",
@@ -1949,7 +1895,7 @@
        "      <td>0.0</td>\n",
        "    </tr>\n",
        "    <tr>\n",
-       "      <th>4</th>\n",
+       "      <th>2</th>\n",
        "      <td>Bulgaria</td>\n",
        "      <td>POLYGON ((27.87917 42.84110, 27.89500 42.80250...</td>\n",
        "      <td>0.0</td>\n",
@@ -1972,63 +1918,111 @@
        "      <td>10.0</td>\n",
        "      <td>0.0</td>\n",
        "    </tr>\n",
+       "    <tr>\n",
+       "      <th>3</th>\n",
+       "      <td>Denmark</td>\n",
+       "      <td>MULTIPOLYGON (((11.51389 54.82972, 11.56444 54...</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>5.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>5.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>6.0</td>\n",
+       "      <td>...</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>31.0</td>\n",
+       "      <td>9.0</td>\n",
+       "      <td>7.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>22.0</td>\n",
+       "      <td>0.0</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>4</th>\n",
+       "      <td>Ireland</td>\n",
+       "      <td>MULTIPOLYGON (((-9.65639 53.22222, -9.66333 53...</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>3.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>3.0</td>\n",
+       "      <td>...</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>53.0</td>\n",
+       "      <td>2.0</td>\n",
+       "      <td>3.0</td>\n",
+       "      <td>0.0</td>\n",
+       "      <td>63.0</td>\n",
+       "      <td>0.0</td>\n",
+       "    </tr>\n",
        "  </tbody>\n",
        "</table>\n",
-       "<p>5 rows × 49 columns</p>\n",
+       "<p>5 rows × 48 columns</p>\n",
        "</div>"
       ],
       "text/plain": [
        "                     NAME                                           geometry  \\\n",
-       "0              Azerbaijan  MULTIPOLYGON (((45.08332 39.76804, 45.26639 39...   \n",
-       "1                 Albania  POLYGON ((19.43621 41.02107, 19.45055 41.06000...   \n",
-       "2                 Armenia  MULTIPOLYGON (((45.57305 40.63249, 45.52888 40...   \n",
-       "3  Bosnia and Herzegovina  POLYGON ((17.64984 42.88908, 17.57853 42.94382...   \n",
-       "4                Bulgaria  POLYGON ((27.87917 42.84110, 27.89500 42.80250...   \n",
+       "0                 Albania  POLYGON ((19.43621 41.02107, 19.45055 41.06000...   \n",
+       "1  Bosnia and Herzegovina  POLYGON ((17.64984 42.88908, 17.57853 42.94382...   \n",
+       "2                Bulgaria  POLYGON ((27.87917 42.84110, 27.89500 42.80250...   \n",
+       "3                 Denmark  MULTIPOLYGON (((11.51389 54.82972, 11.56444 54...   \n",
+       "4                 Ireland  MULTIPOLYGON (((-9.65639 53.22222, -9.66333 53...   \n",
        "\n",
        "   Albania  Andorra  Austria  Belarus  Belgium  Bosnia and Herzegovina  \\\n",
-       "0      NaN      NaN      NaN      NaN      NaN                     NaN   \n",
-       "1      0.0      0.0      1.0      0.0      0.0                     0.0   \n",
-       "2      NaN      NaN      NaN      NaN      NaN                     NaN   \n",
-       "3      0.0      0.0      1.0      0.0      0.0                     2.0   \n",
-       "4      0.0      0.0      3.0      0.0      4.0                     0.0   \n",
+       "0      0.0      0.0      1.0      0.0      0.0                     0.0   \n",
+       "1      0.0      0.0      1.0      0.0      0.0                     2.0   \n",
+       "2      0.0      0.0      3.0      0.0      4.0                     0.0   \n",
+       "3      0.0      0.0      5.0      0.0      5.0                     1.0   \n",
+       "4      0.0      0.0      1.0      0.0      3.0                     0.0   \n",
        "\n",
        "   Bulgaria  Croatia  ...  San Marino  Serbia  Slovakia  Slovenia  Spain  \\\n",
-       "0       NaN      NaN  ...         NaN     NaN       NaN       NaN    NaN   \n",
-       "1       0.0      0.0  ...         0.0     0.0       0.0       1.0    0.0   \n",
-       "2       NaN      NaN  ...         NaN     NaN       NaN       NaN    NaN   \n",
-       "3       0.0      1.0  ...         0.0     3.0       0.0       1.0    0.0   \n",
-       "4       6.0      0.0  ...         0.0     2.0       0.0       0.0    8.0   \n",
+       "0       0.0      0.0  ...         0.0     0.0       0.0       1.0    0.0   \n",
+       "1       0.0      1.0  ...         0.0     3.0       0.0       1.0    0.0   \n",
+       "2       6.0      0.0  ...         0.0     2.0       0.0       0.0    8.0   \n",
+       "3       1.0      6.0  ...         0.0     2.0       0.0       2.0   31.0   \n",
+       "4       1.0      3.0  ...         0.0     0.0       1.0       0.0   53.0   \n",
        "\n",
        "   Sweden  Switzerland  Ukraine  United Kingdom  Vatican City  \n",
-       "0     NaN          NaN      NaN             NaN           NaN  \n",
-       "1     0.0          0.0      0.0             1.0           0.0  \n",
-       "2     NaN          NaN      NaN             NaN           NaN  \n",
-       "3     3.0          1.0      0.0             0.0           0.0  \n",
-       "4     0.0          1.0      0.0            10.0           0.0  \n",
+       "0     0.0          0.0      0.0             1.0           0.0  \n",
+       "1     3.0          1.0      0.0             0.0           0.0  \n",
+       "2     0.0          1.0      0.0            10.0           0.0  \n",
+       "3     9.0          7.0      0.0            22.0           0.0  \n",
+       "4     2.0          3.0      0.0            63.0           0.0  \n",
        "\n",
-       "[5 rows x 49 columns]"
+       "[5 rows x 48 columns]"
       ]
      },
-     "execution_count": 128,
+     "execution_count": 195,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "# Some countries have column values = 'NaN'. These countries are not in Europe according to the dataset,\n",
-    "# but I choose to include them in the map as 'no data' (i.e. in grey)\n",
+    "# Note the inner join to drop countries that we do not consider part of 'Europe'\n",
+    "# (according to the countries.csv file)\n",
     "yurop = gpd.read_file(\"./datasets/europe.geojson\") \\\n",
     "    .loc[:, ['NAME', 'geometry']] \\\n",
     "    .set_index('NAME') \\\n",
-    "    .join(df_routes_count, how='left') \\\n",
-    "    .reset_index()\n",
+    "    .join(df_routes_count, how='inner') \\\n",
+    "    .reset_index(names='NAME')\n",
     "\n",
     "yurop.head()"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 166,
+   "execution_count": 218,
    "id": "11612845",
    "metadata": {},
    "outputs": [
@@ -2036,11 +2030,11 @@
      "data": {
       "application/vnd.bokehjs_exec.v0+json": "",
       "text/html": [
-       "<script id=\"p7925\">\n",
+       "<script id=\"p13596\">\n",
        "  (function() {\n",
        "    const xhr = new XMLHttpRequest()\n",
        "    xhr.responseType = 'blob';\n",
-       "    xhr.open('GET', \"http://localhost:50851/autoload.js?bokeh-autoload-element=p7925&bokeh-absolute-url=http://localhost:50851&resources=none\", true);\n",
+       "    xhr.open('GET', \"http://localhost:51173/autoload.js?bokeh-autoload-element=p13596&bokeh-absolute-url=http://localhost:51173&resources=none\", true);\n",
        "    xhr.onload = function (event) {\n",
        "      const script = document.createElement('script');\n",
        "      const src = URL.createObjectURL(event.target.response);\n",
@@ -2054,76 +2048,50 @@
      },
      "metadata": {
       "application/vnd.bokehjs_exec.v0+json": {
-       "server_id": "de3272d393da49aba1d3fd3516574d15"
+       "server_id": "3422a6f3dd7d4e33b8dd93a4c485662e"
       }
      },
      "output_type": "display_data"
-    },
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n",
-      "Index(['NAME', 'geometry', 'routes'], dtype='object')\n"
-     ]
     }
    ],
    "source": [
     "from bokeh.events import Tap\n",
-    "from bokeh.models.widgets import MultiSelect, Slider, DateRangeSlider\n",
-    "from bokeh.layouts import row\n",
     "from bokeh.application import Application\n",
     "from bokeh.application.handlers import FunctionHandler\n",
-    "from bokeh.models.ranges import Range1d\n",
     "from bokeh.palettes import Reds\n",
-    "from bokeh.models import LinearColorMapper, LogColorMapper, ColorBar\n",
+    "from bokeh.models import LinearColorMapper, ColorBar\n",
     "from shapely import Point\n",
-    "\n",
-    "yurop_json = yurop.to_json()\n",
+    "from bokeh.models import Title\n",
     "\n",
     "def figure_flights(doc):\n",
-    "    palette = Reds[6]\n",
+    "    palette = Reds[8]\n",
     "    palette = palette[::-1]\n",
     "\n",
     "    color_mapper = LinearColorMapper(palette = palette, low = 0, high = 600)\n",
-    "\n",
+    "    \n",
     "    color_bar = ColorBar(color_mapper = color_mapper, \n",
     "                         width = 20, height = 600,\n",
     "                         label_standoff = 8,\n",
     "                         location = (0,0))\n",
     "\n",
     "    \n",
-    "    p = figure(title = 'Number of flights to each country', \n",
+    "    p = figure(title = '', \n",
     "           frame_height = 600,\n",
     "           frame_width = 800, \n",
     "           toolbar_location = 'below',\n",
     "           tools = \"pan, wheel_zoom, box_zoom, reset\")\n",
     "\n",
-    "    geo_ds = GeoJSONDataSource(geojson=yurop_json)\n",
+    "    geo_ds = GeoJSONDataSource()\n",
     "    \n",
     "    plotted_districts = p.patches('xs','ys', source = geo_ds,\n",
     "                    line_color = 'black', \n",
     "                    line_width = 0.25)\n",
+    "    \n",
+    "    p.add_layout(Title(text=\"WARNING: color scale dynamically changes according to selected country\", \\\n",
+    "                       text_font_style=\"italic\"), 'above')\n",
     "\n",
     "    p.patches(\"xs\",\"ys\", source = geo_ds,\n",
-    "                   fill_color = {\"field\" : \"routes\",\n",
+    "                   fill_color = {\"field\" : \"flights\",\n",
     "                                 \"transform\" : color_mapper},\n",
     "                   line_color = \"gray\", \n",
     "                   line_width = 0.25, \n",
@@ -2133,27 +2101,41 @@
     "    p.ygrid.grid_line_color = None\n",
     "    p.axis.visible = False\n",
     "    \n",
-    "    p.add_tools(HoverTool(renderers = [plotted_districts],\n",
-    "                        tooltips = [(\"Country\",\"@NAME\"),(\"# routes\",\"@routes\")]))\n",
+    "    ht = HoverTool(renderers = [plotted_districts])\n",
+    "    p.add_tools(ht)\n",
+    "    \n",
+    "    def set_gdf_as_datasource(gdf):\n",
+    "        if gdf is None or len(gdf) == 0:\n",
+    "            geo_ds.geojson = yurop.to_json()\n",
+    "            ht.tooltips = [(\"Country\", \"@NAME\")]\n",
+    "            color_mapper.high = 600\n",
+    "            p.title.text = '# flights to each country: click to select country of departure'\n",
+    "        else:\n",
+    "            routes_from_country = gdf.iloc[0, 2:].to_frame(name='flights')\n",
+    "            gdf_country_flights = yurop.set_index('NAME').loc[:, ['geometry']] \\\n",
+    "                .join(routes_from_country) \\\n",
+    "                .reset_index(names='NAME')\n",
+    "\n",
+    "            country = gdf.iloc[0, :]['NAME']\n",
+    "            max_flights = gdf_country_flights['flights'].max()\n",
+    "            \n",
+    "            geo_ds.geojson = gdf_country_flights.to_json()\n",
+    "            ht.tooltips = [(\"Country\", \"@NAME\"), (f\"# flights from {country}\", \"@flights\")]\n",
+    "            p.title.text = f\"# flights to each country from {country}: click to select another country of departure\"\n",
+    "            \n",
+    "            # The max value of the colorscale is dynamically computed to the ceiling of the first two significant \n",
+    "            # digits of the max value\n",
+    "            color_mapper.high = np.round(np.power(10, np.ceil(np.log10(max_flights) * 10) / 10) / 10) * 10\n",
+    "            \n",
+    "    set_gdf_as_datasource(None)\n",
     "\n",
     "    tool = TapTool()\n",
     "    \n",
     "    def event(x):\n",
     "        # Figure out the country that intersects the coordinates we clicked\n",
     "        intersects = yurop[yurop.intersects(Point(x.x, x.y))]\n",
-    "        if len(intersects) == 0:\n",
-    "            return\n",
+    "        set_gdf_as_datasource(intersects)\n",
     "        \n",
-    "        routes_from_country = intersects.iloc[0, 2:].to_frame(name='routes')\n",
-    "        gdf_country_flights = yurop.set_index('NAME').loc[:, ['geometry']] \\\n",
-    "            .join(routes_from_country) \\\n",
-    "            .reset_index()\n",
-    "        print(gdf_country_flights.columns)\n",
-    "        \n",
-    "        geo_ds_country = gdf_country_flights.to_json()\n",
-    "        \n",
-    "        geo_ds.geojson = geo_ds_country\n",
-    "\n",
     "    tap = p.add_tools()\n",
     "    p.on_event(Tap, event)\n",
     "    \n",