Calculate avg time between multiple dates

Question

I have a dataframe that looks like this:

The dataframe is already sorted by part, then by date.

I am trying to find the average days between each date grouped by the Part column.

So the desired output would be:

Part	Avg Days
1	7
2	365

How would you go about processing this data to achieve the desired output?

user_16343464 · Answer

You can groupby "Date", use apply+ diff to get the time delta between consecutive rows, and get the mean:

(df.groupby('Part')['Date']
   .apply(lambda s: s.diff().mean())
   .to_frame()
   .reset_index()
)

output:

Part     Date         
1      7 days
2    365 days