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。
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
如果您的包中碰巧有IPython(您应该),那么它(到目前为止)有一个非常好的持续时间格式器(以浮点秒为单位)。它被用于许多地方,例如%%时间单元格魔法。我喜欢它在短时间内产生的格式:
>>> from IPython.core.magics.execution import _format_time
>>>
>>> for v in range(-9, 10, 2):
... dt = 1.25 * 10**v
... print(_format_time(dt))
1.25 ns
125 ns
12.5 µs
1.25 ms
125 ms
12.5 s
20min 50s
1d 10h 43min 20s
144d 16h 13min 20s
14467d 14h 13min 20s
其他回答
我想这样做,所以写了一个简单的函数。它对我来说非常有用,而且非常通用(支持年到微秒,以及任何粒度级别,例如,你可以选择“2天4小时48分钟”和“2天4小时”和“2天4.8小时”等。
def pretty_print_timedelta(t, max_components=None, max_decimal_places=2):
'''
Print a pretty string for a timedelta.
For example datetime.timedelta(days=2, seconds=17280) will be printed as '2 days, 4 hours, 48 minutes'. Setting max_components to e.g. 1 will change this to '2.2 days', where the
number of decimal points can also be set.
'''
time_scales = [timedelta(days=365), timedelta(days=1), timedelta(hours=1), timedelta(minutes=1), timedelta(seconds=1), timedelta(microseconds=1000), timedelta(microseconds=1)]
time_scale_names_dict = {timedelta(days=365): 'year',
timedelta(days=1): 'day',
timedelta(hours=1): 'hour',
timedelta(minutes=1): 'minute',
timedelta(seconds=1): 'second',
timedelta(microseconds=1000): 'millisecond',
timedelta(microseconds=1): 'microsecond'}
count = 0
txt = ''
first = True
for scale in time_scales:
if t >= scale:
count += 1
if count == max_components:
n = t / scale
else:
n = int(t / scale)
t -= n*scale
n_txt = str(round(n, max_decimal_places))
if n_txt[-2:]=='.0': n_txt = n_txt[:-2]
txt += '{}{} {}{}'.format('' if first else ', ', n_txt, time_scale_names_dict[scale], 's' if n>1 else '', )
if first:
first = False
if len(txt) == 0:
txt = 'none'
return txt
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'
def seconds_to_time_left_string(total_seconds):
s = int(total_seconds)
years = s // 31104000
if years > 1:
return '%d years' % years
s = s - (years * 31104000)
months = s // 2592000
if years == 1:
r = 'one year'
if months > 0:
r += ' and %d months' % months
return r
if months > 1:
return '%d months' % months
s = s - (months * 2592000)
days = s // 86400
if months == 1:
r = 'one month'
if days > 0:
r += ' and %d days' % days
return r
if days > 1:
return '%d days' % days
s = s - (days * 86400)
hours = s // 3600
if days == 1:
r = 'one day'
if hours > 0:
r += ' and %d hours' % hours
return r
s = s - (hours * 3600)
minutes = s // 60
seconds = s - (minutes * 60)
if hours >= 6:
return '%d hours' % hours
if hours >= 1:
r = '%d hours' % hours
if hours == 1:
r = 'one hour'
if minutes > 0:
r += ' and %d minutes' % minutes
return r
if minutes == 1:
r = 'one minute'
if seconds > 0:
r += ' and %d seconds' % seconds
return r
if minutes == 0:
return '%d seconds' % seconds
if seconds == 0:
return '%d minutes' % minutes
return '%d minutes and %d seconds' % (minutes, seconds)
for i in range(10):
print pow(8, i), seconds_to_time_left_string(pow(8, i))
Output:
1 1 seconds
8 8 seconds
64 one minute and 4 seconds
512 8 minutes and 32 seconds
4096 one hour and 8 minutes
32768 9 hours
262144 3 days
2097152 24 days
16777216 6 months
134217728 4 years
我接着MarredCheese的回答,加上了年、月、毫秒和微秒
除秒外,所有数字都被格式化为整数,因此秒的分数可以自定义。
@kfmfe04要求几分之一秒,所以我发布了这个解决方案
大体上有一些例子。
from string import Formatter
from datetime import timedelta
def strfdelta(tdelta, fmt='{D:02}d {H:02}h {M:02}m {S:02.0f}s', inputtype='timedelta'):
"""Convert a datetime.timedelta object or a regular number to a custom-
formatted string, just like the stftime() method does for datetime.datetime
objects.
The fmt argument allows custom formatting to be specified. Fields can
include seconds, minutes, hours, days, and weeks. Each field is optional.
Some examples:
'{D:02}d {H:02}h {M:02}m {S:02.0f}s' --> '05d 08h 04m 02s' (default)
'{W}w {D}d {H}:{M:02}:{S:02.0f}' --> '4w 5d 8:04:02'
'{D:2}d {H:2}:{M:02}:{S:02.0f}' --> ' 5d 8:04:02'
'{H}h {S:.0f}s' --> '72h 800s'
The inputtype argument allows tdelta to be a regular number instead of the
default, which is a datetime.timedelta object. Valid inputtype strings:
's', 'seconds',
'm', 'minutes',
'h', 'hours',
'd', 'days',
'w', 'weeks'
"""
# Convert tdelta to integer seconds.
if inputtype == 'timedelta':
remainder = tdelta.total_seconds()
elif inputtype in ['s', 'seconds']:
remainder = float(tdelta)
elif inputtype in ['m', 'minutes']:
remainder = float(tdelta)*60
elif inputtype in ['h', 'hours']:
remainder = float(tdelta)*3600
elif inputtype in ['d', 'days']:
remainder = float(tdelta)*86400
elif inputtype in ['w', 'weeks']:
remainder = float(tdelta)*604800
f = Formatter()
desired_fields = [field_tuple[1] for field_tuple in f.parse(fmt)]
possible_fields = ('Y','m','W', 'D', 'H', 'M', 'S', 'mS', 'µS')
constants = {'Y':86400*365.24,'m': 86400*30.44 ,'W': 604800, 'D': 86400, 'H': 3600, 'M': 60, 'S': 1, 'mS': 1/pow(10,3) , 'µS':1/pow(10,6)}
values = {}
for field in possible_fields:
if field in desired_fields and field in constants:
Quotient, remainder = divmod(remainder, constants[field])
values[field] = int(Quotient) if field != 'S' else Quotient + remainder
return f.format(fmt, **values)
if __name__ == "__main__":
td = timedelta(days=717, hours=3, minutes=5, seconds=8, microseconds=3549)
print(strfdelta(td,'{Y} years {m} months {W} weeks {D} days {H:02}:{M:02}:{S:02}'))
print(strfdelta(td,'{m} months {W} weeks {D} days {H:02}:{M:02}:{S:02.4f}'))
td = timedelta( seconds=8, microseconds=8549)
print(strfdelta(td,'{S} seconds {mS} milliseconds {µS} microseconds'))
print(strfdelta(td,'{S:.0f} seconds {mS} milliseconds {µS} microseconds'))
print(strfdelta(pow(10,7),inputtype='s'))
输出:
1 years 11 months 2 weeks 3 days 01:09:56.00354900211096
23 months 2 weeks 3 days 00:12:20.0035
8.008549 seconds 8 milliseconds 549 microseconds
8 seconds 8 milliseconds 549 microseconds
115d 17h 46m 40s
如果你已经有一个timedelta obj,那么只需将obj转换为字符串。删除字符串的最后3个字符并打印。这将截断秒部分,并以小时:分钟的格式打印其余部分。
t = str(timedeltaobj)
print t[:-3]