将字符串转换为秒

def time_str_to_seconds(time_str):
    parts = time_str.split(':')
    if len(parts) == 3:  # 格式为 "HH:mm:ss"
        hours, minutes, seconds = map(int, parts)
        return hours * 3600 + minutes * 60 + seconds
    elif len(parts) == 2:  # 格式为 "mm:ss"
        minutes, seconds = map(int, parts)
        return minutes * 60 + seconds
    else:  # 假设格式为 "ss"
        return int(parts[0])

# 使用示例
print(time_str_to_seconds("12:34:56"))  # 输出: 45296
print(time_str_to_seconds("01:23"))     # 输出: 83
print(time_str_to_seconds("30"))        # 输出: 30

import re

def is_valid_time_str(time_str):
    pattern = re.compile(r'^(\d{1,2}:){1,2}\d{2}$|^(\d{1,2})$')
    return bool(pattern.match(time_str))

# 使用示例
valid = is_valid_time_str("12:34:56")  # 返回 True
invalid = is_valid_time_str("12:34:60") # 返回 False