Mit Python eine CSV Datei modifizieren (löschen)

mport pandas as pd
import os

directory = '.'

for filename in os.listdir(directory):
    if filename.endswith(".csv") and not filename.startswith('changed_'):
        
        input_file = filename
        output_file = "changed_" + filename

        if not os.path.exists(output_file):
            print(input_file)
            print(output_file)
            df = pd.read_csv(input_file, usecols=range(6))
            dfnew = df.drop('Comment', axis=1)
            export_csv = dfnew.to_csv (output_file, index = None, header=True)