Update 2-Working-With-Data/08-data-preparation/notebook.ipynb

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

2-Working-With-Data/08-data-preparation/notebook.ipynb

@@ -3795,7 +3795,7 @@
         "dirty_data['country_clean'] = dirty_data['country'].str.lower().map(country_mapping)\n",
         "\n",
         "print(\"Before standardization:\")\n",
-        "print(dirty_data[['country']].value_counts())\n",
+        "print(dirty_data['country'].value_counts())\n",
         "print(\"\\nAfter standardization:\")\n",
         "print(dirty_data[['country_clean']].value_counts())"
       ]