我改了一下你的程式碼，實測是可以從 a.csv複製到 b.csv中

import csv

def foo():

with open("a.csv", "r") as f:

reader = csv.DictReader(f)

rows = [row for row in reader]

if not rows:

return

with open("b.csv", mode="w", newline="", errors="ignore") as f2:

for index, row in enumerate(rows):

if index == 0:

f_csv = csv.DictWriter(f2, fieldnames=list(row.keys()))

f_csv.writeheader()

f_csv.writerow(row)

if __name__ == "__main__":

foo()