Question

我有一个200行的DataFrame df。前几行如下所示：

+--------------+----------+----------------+
|Customer name | Arrival  | Actual Arrival | 
+--------------+----------+----------------+
| Customer 21  |       20 |                |
| Customer 22  |       30 |                |  
| Customer 23  |       20 |                | 
| Customer 24  |       10 |                |  
| Customer 25  |       20 |                | 
+--------------+----------+----------------+

“到达”列显示从开始时间开始的分钟到达时间。因此，我想通过向“到达”列值添加固定的时间戳记（“开始时间”）来创建“实际到达”列。例如：如果开始时间为07:00；

+--------------+----------+----------------+
|Customer name | Arrival  | Actual Arrival | 
+--------------+----------+----------------+
| Customer 21  |       20 |    07:20       |
| Customer 22  |       30 |    07:30       |  
| Customer 23  |       20 |    07:20       | 
| Customer 24  |       10 |    07:10       |  
| Customer 25  |       60 |    08:00       | 
+--------------+----------+----------------+

如何在python中做到这一点？

Answer 1

您可以尝试以下方法吗？

import datetime
actual_start_time = datetime.time(7, 0)
start_time = datetime.datetime.combine(datetime.datetime.today().date(), actual_start_time)
df['Actual Arrival'] = df['Arrival'].apply(lambda x: start_time + datetime.timedelta(minutes=x))

示例：

>>> df = pd.DataFrame([[1, 2, 3, 4], [5, 6, 7, 8]]).T
>>> df.columns = ['name', 'Arrival']
>>> df
   name  Arrival
0     1        5
1     2        6
2     3        7
3     4        8
>>> start_time = datetime.datetime.strptime('2019-05-17 7:0:0', '%Y-%m-%d %H:%M:%S')
>>> df['Actual Arrival'] = df['Arrival'].apply(lambda x: start_time + datetime.timedelta(minutes=x))
>>> df
   name  Arrival      Actual Arrival
0     1        5 2019-05-17 07:05:00
1     2        6 2019-05-17 07:06:00
2     3        7 2019-05-17 07:07:00
3     4        8 2019-05-17 07:08:00

如果只想要时间，可以执行以下操作：

>>> df['Actual Arrival'] = df['Arrival'].apply(lambda x: (start_time + datetime.timedelta(minutes=x)).time())
>>> df
   name  Arrival Actual Arrival
0     1        5       07:05:00
1     2        6       07:06:00
2     3        7       07:07:00
3     4        8       07:08:00

Answer 2

如果您只想使用time()作为基准时间，请尝试以下操作：

import datetime
arrival = 20
base = datetime.time(7, 0, 0)  # 07:00:00 or whatever your base time is.
actual_arrival = datetime.time(base.hour, base.minute + arrival, base.second)

这将输出：

07:20:00

编辑：请注意，在上述方法中，time()的参数必须有效，并且如果您的分钟数大于59，则该分钟数将无效。解决方法是，您可以定义一个辅助函数来实现此目的：

def add_times(op1, op2):  # two tuples in this format: (h, m, s)
    hour = op1[0] + op2[0]
    minute = op1[1] + op2[1]
    second = op1[2] + op2[2]

    if second >= 60:
        minute += 1
        second -= 60

    if minute >= 60:
        hour += 1
        minute -= 60

    if hour >= 24:
        hour -= 24

    return (hour, minute, second)

并将代码更改为：

base_time = (7, 0, 0)  # (hour, minute, seconds)
base = datetime.time(*base_time)  # If you want to have it as a time object in your code. It is redundant now.
actual_arrival = datetime.time(*add_times(base_time, (0, 20, 0)))

但是我认为它不再是解决问题的datetime方法。

Answer 3

import datetime
data = {'customers': {0: 'Customer 21',
  1: 'Customer 22',
  2: 'Customer 23',
  3: 'Customer 24',
  4: 'Customer 25'},
 'arrival': {0: 20, 1: 30, 2: 20, 3: 10, 4: 60}}

df = pd.DataFrame(data)

df['actual arrival'] = df.arrival.apply(lambda x:(pd.to_datetime(datetime.datetime.today().date())+pd.offsets.Timedelta(hours=7,minutes=x)).strftime('%H:%M'))

将时间戳添加到分钟

3 个答案: