编写一个叫做 print_time 的函数,接收一个 Time 对象并用 时:分:秒 的格式打印它。提示: 格式化序列 %.2d 可以至少两位数的形式打印一个整数,如果不足则在前面补 0。
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| class Time:
"""用于记录时间
属性：hour, minute, second
"""
def print_time(ti):
print("%.2d:%.2d:%.2d" % (ti.hour,ti.minute,ti.second)) #记得加括号
time1 = Time()
time1.hour = 11
time1.minute = 59
time1.second = 30
print_time(time1)
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编写一个叫做 is_after 的布尔函数,接收两个 Time 对象,t1 和 t2 ,若 t1 的时间在 t2 之后,则返回 True ,否则返回 False。挑战:不要使用 if 语句。
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| class Time:
"""用于记录时间
属性：hour, minute, second
"""
def print_time(ti):
print("%.2d:%.2d:%.2d" % (ti.hour,ti.minute,ti.second)) #记得加括号
def is_after(t1,t2):
return (t1.hour, t1.minute, t1.second) > (t2.hour, t2.minute, t2.second)
time1 = Time()
time1.hour = 11
time1.minute = 59
time1.second = 30
time2 = Time()
time2.hour = 11
time2.minute = 58
time2.second = 30
is_after(time1,time2)
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我们做个练习,编写一个纯函数版本的 increment ,创建并返回一个 Time 对象,而不是修改参数。
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| class Time:
"""用于记录时间
属性：hour, minute, second
"""
def print_time(ti):
print("%.2d:%.2d:%.2d" % (ti.hour,ti.minute,ti.second)) #记得加括号
def increment(t1, seconds):
"""给一个Time对象增加指定的秒数"""
addedtime = Time()
minutes, addedtime.second = divmod(t1.hour * 60 * 60 + t1.minute * 60 + t1.second + seconds, 60)
addedtime.hour, addedtime.minute = divmod(minutes, 60)
return addedtime
time1 = Time()
time1.hour = 11
time1.minute = 59
time1.second = 30
print_time(increment(time1, 90))
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我们再做个练习, 使用 time_to_int 和 int_to_time 重写 increment 函数。
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| class Time:
"""用于记录时间
属性：hour, minute, second
"""
def print_time(ti):
print("%.2d:%.2d:%.2d" % (ti.hour,ti.minute,ti.second)) #记得加括号
def time_to_int(time):
minutes = time.hour * 60 + time.minute
seconds = minutes * 60 + time.second
return seconds
def int_to_time(seconds):
time = Time()
minutes, time.second = divmod(seconds, 60)
time.hour, time.minute = divmod(minutes, 60)
return time
def add_time(t1, t2):
seconds = time_to_int(t1) + time_to_int(t1)
return int_to_time(seconds)
def increment(t1,seconds):
"""给一个Time对象增加指定的秒数"""
return int_to_time(time_to_int(t1) + seconds)
def add_time(t1, t2):
assert valid_time(t1) and valid_time(t2)
seconds = time_to_int(t1) + time_to_int(t2)
return int_to_time(seconds)
time1 = Time()
time1.hour = 11
time1.minute = 59
time1.second = 30
print_time(increment(time1, 90))
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