Question

我正在尝试使用this线程中的代码从列表中计算平均时间。所有其他代码建议对我来说都不起作用，因为他们考虑持续时间而不是时间。

import datetime
import math
import numpy

def datetime_to_radians(x):
    # radians are calculated using a 24-hour circle, not 12-hour, starting at north and moving clockwise
    time_of_day = x.time()
    seconds_from_midnight = 3600 * time_of_day.hour + 60 * time_of_day.minute + time_of_day.second
    radians = float(seconds_from_midnight) / float(12 * 60 * 60) * 2.0 * math.pi
    return radians

def average_angle(angles):
    # angles measured in radians
    x_sum = numpy.sum([math.sin(x) for x in angles])
    y_sum = numpy.sum([math.cos(x) for x in angles])
    x_mean = x_sum / float(len(angles))
    y_mean = y_sum / float(len(angles))
    return numpy.arctan2(x_mean, y_mean)

def radians_to_time_of_day(x):
    # radians are measured clockwise from north and represent time in a 24-hour circle
    seconds_from_midnight = int(float(x) / (2.0 * math.pi) * 12.0 * 60.0 * 60.0)
    hour = seconds_from_midnight / 3600
    minute = (seconds_from_midnight % 3600) / 60
    second = seconds_from_midnight % 60
    return datetime.time(hour, minute, second)

def average_times_of_day(x):
    # input datetime.datetime array and output datetime.time value
    angles = [datetime_to_radians(y) for y in x]
    avg_angle = average_angle(angles)
    return radians_to_time_of_day(avg_angle)

average_times_of_day([datetime.datetime(2017, 6, 9, 0, 10), datetime.datetime(2017, 6, 9, 0, 20)])
# datetime.time(0, 15)

average_times_of_day([datetime.datetime(2017, 6, 9, 23, 50), datetime.datetime(2017, 6, 9, 0, 10)])
# datetime.time(0, 0)

我收到以下错误：

TypeError: integer argument expected, got float

有人可以帮忙吗？

Answer 1

这是另一个只能考虑小时和分钟才能处理日期时间对象列表的解决方案：

from cmath import phase
from cmath import rect
import datetime
from math import degrees
from math import radians

dfList = ([datetime.datetime(2017, 9, 15, 8, 8),
           datetime.datetime(2017, 9, 14, 8, 5),
           datetime.datetime(2017, 9, 13, 6, 56),
           datetime.datetime(2017, 12, 9, 6, 14),
           datetime.datetime(2017, 11, 9, 6, 42)])

dfList = [item.strftime("%H:%M") for item in dfList]


def mean_angle(deg):
    return degrees(phase(sum(rect(1, radians(d)) for d in deg) / len(deg)))


def mean_time(times):
    t = (time.split(':') for time in times)
    seconds = ((int(m) * 60 + int(h) * 3600)
               for h, m in t)
    day = 24 * 60 * 60
    to_angles = [s * 360. / day for s in seconds]
    mean_as_angle = mean_angle(to_angles)
    mean_seconds = mean_as_angle * day / 360.
    if mean_seconds < 0:
        mean_seconds += day
    h, m = divmod(mean_seconds, 3600)
    m, s = divmod(m, 60)
    return '%02i:%02i' % (h, m)


print(mean_time(dfList))

Answer 2

您的代码在Python 2.7中运行良好，但在Python 3.6中运行良好。

错误引自第26行return datetime.time(hour, minute, second)。

将hour，minute和second的值转换为int()后，效果正常。

def radians_to_time_of_day(x):
    # radians are measured clockwise from north and represent time in a 24-hour circle
    seconds_from_midnight = int(float(x) / (2.0 * math.pi) * 12.0 * 60.0 * 60.0)
    hour = int(seconds_from_midnight / 3600)
    minute = int((seconds_from_midnight % 3600) / 60)
    second = int(seconds_from_midnight % 60)
    return datetime.time(hour, minute, second)

Answer 3

在Python 3中，即使两个操作数都是整数，/也会执行真（浮动）除法。

使用//代替

def radians_to_time_of_day(x):
    # radians are measured clockwise from north and represent time in a 24-hour circle
    seconds_from_midnight = int(float(x) / (2.0 * math.pi) * 12.0 * 60.0 * 60.0)
    hour = seconds_from_midnight // 3600
    minute = (seconds_from_midnight % 3600) // 60
    second = seconds_from_midnight % 60
    return datetime.time(hour, minute, second)

计算列表产生错误的平均时间

3 个答案: