如何在Python中为CSV文件中的空单元格编写函数？

import csv

def replace_empty_cells(csv_file):
    # 读取CSV文件
    with open(csv_file, 'r') as file:
        reader = csv.reader(file)
        rows = list(reader)

    # 遍历每一行并替换空单元格
    for row in rows:
        for i in range(len(row)):
            if row[i] == '':
                row[i] = 'N/A'  # 可以根据需求替换为空单元格的内容

    # 将修改后的数据写回CSV文件
    with open(csv_file, 'w', newline='') as file:
        writer = csv.writer(file)
        writer.writerows(rows)

replace_empty_cells('path/to/your/csv/file.csv')