fixed writer.sheets['Recommended Trades'] issue

Author: nickmccullum

starter_files/001_equal_weight_S&P_500.ipynb

@@ -254,12 +254,12 @@
    "source": [
     "### Applying the Formats to the Columns of Our `.xlsx` File\n",
     "\n",
-    "We can use the `set_column` method applied to the `writer.book` object to apply formats to specific columns of our spreadsheets.\n",
+    "We can use the `set_column` method applied to the `writer.sheets['Recommended Trades']` object to apply formats to specific columns of our spreadsheets.\n",
     "\n",
     "Here's an example:\n",
     "\n",
     "```python\n",
-    "writer.book.set_column('B:B', #This tells the method to apply the format to column B\n",
+    "writer.sheets['Recommended Trades'].set_column('B:B', #This tells the method to apply the format to column B\n",
     "                     18, #This tells the method to apply a column width of 18 pixels\n",
     "                     string_template #This applies the format 'string_template' to the column\n",
     "                    )\n",