You may have efficiently written your pandas Dataframe to an Excel file, however whenever you open it, all of the columns are squashed up in opposition to one another.
There may be a simple repair to auto-adjusting your column widths.
Auto Adjusting Column Widths in Pandas
author = pd.ExcelWriter('file.xlsx')
df.to_excel(author, sheet_name='sheetName', index=False, na_rep='NaN')
for column in df:
column_length = max(df[column].astype(str).map(len).max(), len(column))
col_idx = df.columns.get_loc(column)
author.sheets['sheetName'].set_column(col_idx, col_idx, column_length)
author.save()
