一种方法是读入所有数据，然后用标头覆盖文件，然后再次写出数据。对于大型CSV文件，这可能不可行：
#!python3import csvwith open('file.csv',newline='') as f: r = csv.reader(f) data = [line for line in r]with open('file.csv','w',newline='') as f: w = csv.writer(f) w.writerow(['ColA','ColB']) w.writerows(data)
