当秒小于或等于60秒时，显示时间为1零

seconds = 45
time_str = f"{seconds:02d}" if seconds > 9 else f"{seconds:d}"
print(time_str)  # 输出: 45

seconds = 7
time_str = "{:02d}".format(seconds) if seconds > 9 else str(seconds)
print(time_str)  # 输出: 7

seconds = 30
time_str = str(seconds).zfill(2) if seconds > 9 else str(seconds)
print(time_str)  - 输出: 30