将HH:MM:SS列转换为ZT时间

import datetime

def convert_to_zt_time(time_str):
    # 解析时间字符串
    hours, minutes, seconds = map(int, time_str.split(':'))
    
    # 考虑时区差异，这里为0
    timezone_diff = datetime.timedelta(hours=0)
    
    # 转换为ZT时间
    zt_time = datetime.datetime(1, 1, 1, hours, minutes, seconds) - timezone_diff
    
    # 格式化输出
    zt_time_str = zt_time.strftime('%H:%M:%S')
    
    return zt_time_str

# 示例输入
time_str = '12:34:56'

# 转换为ZT时间
zt_time_str = convert_to_zt_time(time_str)

print(zt_time_str)  # 输出结果：12:34:56