How to find duration between two time difference in python dataframe

Question

I have raw data like this want to find the difference between this two time in mint .....problem is data which is in data frame... source:

   start time   end time
0   08:30:00    17:30:00
1   11:00:00    17:30:00
2   08:00:00    21:30:00
3   19:30:00    22:00:00
4   19:00:00    00:00:00
5   08:30:00    15:30:00

Need a output like this:

duration
 540mint
 798mint
 162mint
 1140mint
 420mint

Possible duplicate of [Date difference in minutes in Python](https://stackoverflow.com/questions/2788871/date-difference-in-minutes-in-python) — Jonas, Jun 08 '18 at 05:52
How are you calculating the time differences? 08:30:00 - 17:30:00 = -9 hours, not 120 minutes. — l'L'l, Jun 08 '18 at 06:06
If you're going to show an example I would suggest it be representative of the actual correct output. — l'L'l, Jun 08 '18 at 06:11
Your input is unclear. When you say dataframe, do you mean pandas? If so, the question should be tagged accordingly. — Mr. T, Jun 08 '18 at 07:58
Also, please clarify, if you want a solution in R or in Python. — Mr. T, Jun 08 '18 at 08:07
From `19:00:00` to `00:00:00` is normally only 5 hours? i.e. 300 minutes. — Martin Evans, Jun 08 '18 at 08:24

score 0 · Answer 1 · answered Jun 08 '18 at 06:18

Your expected output seems to be incorrect. That aside, we can use base R's difftime:

transform(
    df,
    duration = difftime(
        strptime(end.time, format = "%H:%M:%S"),
        strptime(start.time, format = "%H:%M:%S"),
        units = "mins"))
#  start.time end.time   duration
#0   08:30:00 17:30:00   540 mins
#1   11:00:00 17:30:00   390 mins
#2   08:00:00 21:30:00   810 mins
#3   19:30:00 22:00:00   150 mins
#4   19:00:00 00:00:00 -1140 mins
#5   08:30:00 15:30:00   420 mins

or as a difftime vector

with(df, difftime(
    strptime(end.time, format = "%H:%M:%S"),
    strptime(start.time, format = "%H:%M:%S"),
    units = "mins"))
#Time differences in mins
#[1]   540   390   810   150 -1140   420

Sample data

df <- read.table(text =
    "   'start time'   'end time'
0   08:30:00    17:30:00
1   11:00:00    17:30:00
2   08:00:00    21:30:00
3   19:30:00    22:00:00
4   19:00:00    00:00:00
5   08:30:00    15:30:00", header = T, row.names = 1)

This is a Python question. Not sure, why you suggest a solution in R. — Mr. T, Jun 08 '18 at 07:54
@Mr.T it was tagged as an R question at first. Check the edits. — Maurits Evers, Jun 08 '18 at 08:02

cosmic_inquiry · Answer 2 · 2018-06-08T06:42:38.663

import pandas as pd

df = pd.DataFrame({'start time':['08:30:00','11:00:00','08:00:00','19:30:00','19:00:00','08:30:00'],'end time':['17:30:00','17:30:00','21:30:00','22:00:00','00:00:00','15:30:00']},columns=['start time','end time'])

df
Out[355]:
  start time  end time
0   08:30:00  17:30:00
1   11:00:00  17:30:00
2   08:00:00  21:30:00
3   19:30:00  22:00:00
4   19:00:00  00:00:00
5   08:30:00  15:30:00

(pd.to_datetime(df['end time']) - pd.to_datetime(df['start time'])).dt.seconds/60
Out[356]:
0    540.0
1    390.0
2    810.0
3    150.0
4    300.0
5    420.0
dtype: float64

score -1 · Answer 3 · answered Jun 08 '18 at 05:59

Yes, definitely datetime is what you need here. Specifically, the strptime function, which parses a string into a time object.

from datetime import datetime
s1 = '10:33:26'
s2 = '11:15:49' # for example
FMT = '%H:%M:%S'
tdelta = datetime.strptime(s2, FMT) - datetime.strptime(s1, FMT)

That gets you a timedelta object that contains the difference between the two times. You can do whatever you want with that, e.g. converting it to seconds or adding it to another datetime.

This will return a negative result if the end time is earlier than the start time, for example s1 = 12:00:00 and s2 = 05:00:00. If you want the code to assume the interval crosses midnight in this case (i.e. it should assume the end time is never earlier than the start time), you can add the following lines to the above code:

if tdelta.days < 0:
    tdelta = timedelta(days=0,
                seconds=tdelta.seconds, microseconds=tdelta.microseconds)

(of course you need to include from datetime import timedelta somewhere). Thanks to J.F. Sebastian for pointing out this use case.

see [more](https://stackoverflow.com/questions/3096953/how-to-calculate-the-time-interval-between-two-time-strings/3096984#3096984) — Morteza M, Jun 08 '18 at 06:00

How to find duration between two time difference in python dataframe

3 Answers3

Sample data