在Python中添加持续时间

Question

我想在Python中添加一系列拆分。《纽约时报》以“00:08:30.291”开头。我似乎找不到正确的方法来使用Python对象或API来使这变得方便/优雅。似乎time对象不使用微秒，所以我正在使用datetime的strtime成功地解析字符串。但是日期时间似乎没有增加，我真的不想超过几天（即23+2小时=25小时）。我可以使用datetime.time，但它们也不添加。时间增量似乎是合适的，但从/到其他事物的转换似乎有点尴尬。也许我遗漏了一些显而易见的东西。我希望能够：

for timestring in times:
    t = datetime.strptime("%H:%M:%S.%f", timestring).time
    total_duration = total_duration + t
print total_duration.strftime("%H:%M:%S.%f")

Answer 1

import numpy as np

# read file with one duration per line
with open('clean_times.txt', 'r') as f:
    x = f.read()

# Convert string to list of '00:02:12.31'
# I had to drop last item (empty string)
tmp = x.split('\n')[:-1]

# get list of ['00', 02, '12.31']
tmp = [i.split(':') for i in tmp.copy()]

# create numpy array with floats
np_tmp = np.array(tmp, dtype=np.float)

# sum via columns and divide
# hours/24 minutes/60 milliseconds/1000
# X will be a float array [days, hours, seconds]
# Something like `array([ 0.        , 15.68333333,  7.4189    ])`
X = np_tmp.sum(axis=0) / np.array([24, 60, 1000])

我在这里很好，但如果你需要像'15:41:07.518'这样的花哨的字符串 作为输出，继续读取

# X will be a float array [hours, hours, seconds]
X = np_tmp.sum(axis=0) / np.array([1, 60, 1000])

# ugly part
# Hours are integer parts
H = int(X[0]) + int(X[1])
# Minutes are  hour fractional part and integer minutes part
tmp_M = (X[0] % 1 + X[1] % 1) * 60
M = int(tmp_M)
# Seconds are minutes fractional part and integer seconds part
tmp_S = tmp_M % 1 * 60 + X[2]
S = int(tmp_S)
# Milliseconds are seconds fractional part
MS = int(tmp_S % 1 * 1000)

# merge string for output
# Something like '15:41:07.518'
result = f'{H:02}:{M:02}:{S:02}.{MS:03}'

Answer 2

您正在处理的是时间差异，这就是为什么使用^{}仅适用于以下情况：

>>> import datetime
>>> d1 = datetime.datetime.strptime("00:08:30.291", "%H:%M:%S.%f")
>>> d1
datetime.datetime(1900, 1, 1, 0, 8, 30, 291000)
>>> d2
datetime.datetime(1900, 1, 1, 0, 2, 30, 291000)
>>> dt1 = datetime.timedelta(minutes=d1.minute, seconds=d1.second, microseconds=d1.microsecond)
>>> dt2 = datetime.timedelta(minutes=d2.minute, seconds=d2.second, microseconds=d2.microsecond)
>>> fin = dt1 + dt2
>>> fin
datetime.timedelta(0, 660, 582000)
>>> str(fin)
'0:11:00.582000'

另外，请不要对变量使用sum这样的名称，您正在隐藏内置的。