How to convert Python datetime dates to decimal/float years

Question

I am looking for a way to convert datetime objects to decimal(/float) year, including fractional part. Example:

>>> obj = SomeObjet()
>>> o         


        

Answer 1

After implementing the accepted solution, I had the revelation that this modern pandas version is identical, and much simpler:

dat['decimal_date']=dat.index.year+ (dat.index.dayofyear -1)/365

Must be used on a date-time index Pandas dataframe. Adding as this solution post comes up in the top of my google search for this issue.