我在格式化日期时间时遇到了麻烦。timedelta对象。
这就是我想做的: 我有一个对象列表，对象类的成员之一是显示事件持续时间的timedelta对象。我想以小时:分钟的格式显示这个持续时间。
我尝试了各种方法来做这件事，但我有困难。我目前的方法是为返回小时和分钟的对象在类中添加方法。我可以通过除以time得到小时数。秒乘以3600，四舍五入。我在得到剩余的秒并将其转换为分钟时遇到了麻烦。
顺便说一下，我使用谷歌AppEngine和Django模板来表示。
当前回答
Timedelta到字符串，用于打印运行时间信息。
def strfdelta_round(tdelta, round_period='second'):
"""timedelta to string, use for measure running time
attend period from days downto smaller period, round to minimum period
omit zero value period
"""
period_names = ('day', 'hour', 'minute', 'second', 'millisecond')
if round_period not in period_names:
raise Exception(f'round_period "{round_period}" invalid, should be one of {",".join(period_names)}')
period_seconds = (86400, 3600, 60, 1, 1/pow(10,3))
period_desc = ('days', 'hours', 'mins', 'secs', 'msecs')
round_i = period_names.index(round_period)
s = ''
remainder = tdelta.total_seconds()
for i in range(len(period_names)):
q, remainder = divmod(remainder, period_seconds[i])
if int(q)>0:
if not len(s)==0:
s += ' '
s += f'{q:.0f} {period_desc[i]}'
if i==round_i:
break
if i==round_i+1:
s += f'{remainder} {period_desc[round_i]}'
break
return s
例如，自动省略零前导周期:
>>> td = timedelta(days=0, hours=2, minutes=5, seconds=8, microseconds=3549)
>>> strfdelta_round(td, 'second')
'2 hours 5 mins 8 secs'
或者省略中间的零周期:
>>> td = timedelta(days=2, hours=0, minutes=5, seconds=8, microseconds=3549)
>>> strfdelta_round(td, 'millisecond')
'2 days 5 mins 8 secs 3 msecs'
或舍入至分钟，省略以下分钟:
>>> td = timedelta(days=1, hours=2, minutes=5, seconds=8, microseconds=3549)
>>> strfdelta_round(td, 'minute')
'1 days 2 hours 5 mins'
其他回答
Timedelta到字符串，用于打印运行时间信息。
def strfdelta_round(tdelta, round_period='second'):
"""timedelta to string, use for measure running time
attend period from days downto smaller period, round to minimum period
omit zero value period
"""
period_names = ('day', 'hour', 'minute', 'second', 'millisecond')
if round_period not in period_names:
raise Exception(f'round_period "{round_period}" invalid, should be one of {",".join(period_names)}')
period_seconds = (86400, 3600, 60, 1, 1/pow(10,3))
period_desc = ('days', 'hours', 'mins', 'secs', 'msecs')
round_i = period_names.index(round_period)
s = ''
remainder = tdelta.total_seconds()
for i in range(len(period_names)):
q, remainder = divmod(remainder, period_seconds[i])
if int(q)>0:
if not len(s)==0:
s += ' '
s += f'{q:.0f} {period_desc[i]}'
if i==round_i:
break
if i==round_i+1:
s += f'{remainder} {period_desc[round_i]}'
break
return s
例如，自动省略零前导周期:
>>> td = timedelta(days=0, hours=2, minutes=5, seconds=8, microseconds=3549)
>>> strfdelta_round(td, 'second')
'2 hours 5 mins 8 secs'
或者省略中间的零周期:
>>> td = timedelta(days=2, hours=0, minutes=5, seconds=8, microseconds=3549)
>>> strfdelta_round(td, 'millisecond')
'2 days 5 mins 8 secs 3 msecs'
或舍入至分钟，省略以下分钟:
>>> td = timedelta(days=1, hours=2, minutes=5, seconds=8, microseconds=3549)
>>> strfdelta_round(td, 'minute')
'1 days 2 hours 5 mins'
我有一个函数:
def period(delta, pattern):
d = {'d': delta.days}
d['h'], rem = divmod(delta.seconds, 3600)
d['m'], d['s'] = divmod(rem, 60)
return pattern.format(**d)
例子:
>>> td = timedelta(seconds=123456789)
>>> period(td, "{d} days {h}:{m}:{s}")
'1428 days 21:33:9'
>>> period(td, "{h} hours, {m} minutes and {s} seconds, {d} days")
'21 hours, 33 minutes and 9 seconds, 1428 days'
我个人使用humanize库:
>>> import datetime
>>> humanize.naturalday(datetime.datetime.now())
'today'
>>> humanize.naturalday(datetime.datetime.now() - datetime.timedelta(days=1))
'yesterday'
>>> humanize.naturalday(datetime.date(2007, 6, 5))
'Jun 05'
>>> humanize.naturaldate(datetime.date(2007, 6, 5))
'Jun 05 2007'
>>> humanize.naturaltime(datetime.datetime.now() - datetime.timedelta(seconds=1))
'a second ago'
>>> humanize.naturaltime(datetime.datetime.now() - datetime.timedelta(seconds=3600))
'an hour ago'
当然，它并没有给您所寻找的确切答案(实际上是str(timeA - timeB)，但我发现，一旦超过几个小时，显示很快就变得不可读了。Humanize支持更大的值，这些值是人类可读的，而且本地化得很好。
它的灵感来自于Django的贡献。humanize模块，显然，既然你在使用Django，你应该使用它。
您可以使用str()将timedelta转换为字符串。这里有一个例子:
import datetime
start = datetime.datetime(2009,2,10,14,00)
end = datetime.datetime(2009,2,10,16,00)
delta = end-start
print(str(delta))
# prints 2:00:00
提问者想要一个比典型的更好的格式:
>>> import datetime
>>> datetime.timedelta(seconds=41000)
datetime.timedelta(0, 41000)
>>> str(datetime.timedelta(seconds=41000))
'11:23:20'
>>> str(datetime.timedelta(seconds=4102.33))
'1:08:22.330000'
>>> str(datetime.timedelta(seconds=413302.33))
'4 days, 18:48:22.330000'
所以，实际上有两种格式，一种是天数为0，它被省略了，另一种是文本“n天，h:m:s”。但是，秒可能有分数，打印输出中没有前导0，所以列很乱。
如果你喜欢，下面是我的日常工作:
def printNiceTimeDelta(stime, etime):
delay = datetime.timedelta(seconds=(etime - stime))
if (delay.days > 0):
out = str(delay).replace(" days, ", ":")
else:
out = "0:" + str(delay)
outAr = out.split(':')
outAr = ["%02d" % (int(float(x))) for x in outAr]
out = ":".join(outAr)
return out
返回dd:hh:mm:ss格式的输出:
00:00:00:15
00:00:00:19
02:01:31:40
02:01:32:22
我确实想过在上面加上年份，但这是留给读者的练习，因为超过1年的输出是安全的:
>>> str(datetime.timedelta(seconds=99999999))
'1157 days, 9:46:39'
