如何计算以秒为单位的时间差？

import time

def calculate_time_difference(start_time, end_time):
    start_timestamp = int(time.mktime(time.strptime(start_time, "%Y-%m-%d %H:%M:%S")))
    end_timestamp = int(time.mktime(time.strptime(end_time, "%Y-%m-%d %H:%M:%S")))
    time_difference = end_timestamp - start_timestamp
    return time_difference

start_time = "2022-01-01 00:00:00"
end_time = "2022-01-01 00:00:10"
time_difference = calculate_time_difference(start_time, end_time)
print("时间差（秒）：", time_difference)