我尝试将CSV文件第一列中的日期转换为元组，以便查找该列中的所有日期与当前日期之间的差异，但我收到以下错误：

"ValueError: time data '2023-04-05' does not match format '%Y,%d,%m'"

这就是我目前所拥有的：

from csv import reader
from datetime import datetime

# open file in read mode
with open("food.csv", "r") as read_obj:
    # pass the file object to reader() to get the reader object
    csv_reader = reader(read_obj)
    # Iterate over each row in the csv using reader object

    for row in csv_reader:
        # row variable is a list that represents a row in csv

        date_str = row[0].strip("-")
        fmt = "%Y,%d,%m"

        date_obj = datetime.strptime(date_str, fmt)

        t_tuple = date_obj.timetuple()

        print(t_tuple)