Difference between two dates in Pandas DataFrame

Question

I have many columns in a data frame and I have to find the difference of time in two column named as in_time and out_time and put it in the new column in the same data frame.

The format of time is like this 2015-09-25T01:45:34.372Z.

I am using Pandas DataFrame.

I want to do like this:

df.days = df.out_time - df.in_time

I have many columns and I have to increase 1 more column in it named days and put the differences there.

Answer 1

You need to convert the strings to datetime dtype, you can then subtract whatever arbitrary date you want and on the resulting series call dt.days:

In [15]:
df = pd.DataFrame({'date':['2015-09-25T01:45:34.372Z']})
df

Out[15]:
                       date
0  2015-09-25T01:45:34.372Z

In [19]:
df['date'] = pd.to_datetime(df['date'])
df['day'] = (df['date'] - dt.datetime.now()).dt.days
df

Out[19]:
                     date  day
0 2015-09-25 01:45:34.372 -252