Python Pandas: TypeError: unsupported operand type(s) for +: 'datetime.time' and 'Timedelta'

Question

I am attempting to add two series in a dataframe in pandas with the first series being a 24-hr time value (e.g. 17:30) exported from an excel file and the second series bein

Answer 1

The cause

The error is pretty clear. If you check the types of the elements, you will find out that at some point you are tying to add datetime.time object and pandas.Timedelta.

There are 2 kinds of dates, times and timedeltas:

• python's builtin from datetime module i.e. datetime.time, datetime.date, datetime.timedelta, ...
• pandas / numpy i.e pandas.Timestamp, pandas.Timedelta

these two stacks are incompatible for basic operations as addition or comparison.

Solution 1

Convert everything to pandas type and extract the times in the end

You should make sure, that dtypes of your columns are something like datetime64[ns] and timedelta64[ns]. For that, try converting them explicitly using pd.to_datetime and pd.to_timedelta.

Solution 2

Another approach would be just converting the Delta column to datetime.timedelta you could try

df["end_Time"] = df["Start_Time"] + df["Delta"].map(pd.Timedelta.to_pytimedelta)

But you may run into some more errors depending on what is in your df["Delta"] and df["Start_Time"]

Answer 2

Try this:

import datetime as dt

df["end_Time"] = df["Start_Time"] + df["Delta"].map(dt.timedelta)