Yes, you can export a DataFrame to an existing CSV file without overwriting its contents. To achieve this, you can open the file in append mode ('a') and use the to_csv function with the header parameter set to False. Here's an example: df.to_csv('existing_file.csv', mode='a', header=False) In the above example, the DataFrame will be appended to the existing CSV file named 'existing_file.csv' without overwriting its contents. The header=False parameter ensures that the column names are not repeated.