Adding column with values from one dataframe to another based on same datetime

I have a sample dataframe df1

DateTime            Values  2020-12-26 14:00:00 439.0  2020-12-26 14:00:00 441.0  2020-12-26 14:00:00 461.0  2020-12-27 08:00:00 536.0  2020-12-27 08:00:00 547.0  2020-12-27 08:00:00 484.0  2020-12-27 08:00:00 497.0  2020-12-27 14:00:00 491.0  2020-12-27 14:00:00 512.0  2020-12-27 14:00:00 529.0  2020-12-27 14:00:00 436.0  

and another dataframe df 2

DateTime            Trend     2020-12-18 14:00    no trend      2020-12-19 08:00    no trend      2020-12-19 14:00    no trend      2020-12-21 08:00    no trend          2020-12-21 14:00    no trend      2020-12-22 08:00    no trend      2020-12-22 14:00    decreasing    2020-12-23 08:00    no trend      2020-12-23 14:00    no trend      2020-12-24 08:00    no trend      2020-12-24 14:00    no trend      2020-12-25 08:00    no trend      2020-12-25 14:00    decreasing    2020-12-26 08:00    no trend  2020-12-26 14:00    decreasing    2020-12-27 08:00    no trend      2020-12-27 14:00    no trend      

I am trying to create a new column df1[Trend] and assign the trend values based on the right date time

The result should be like this

DateTime            Values    Trend  2020-12-26 14:00:00 439.0     decreasing  2020-12-26 14:00:00 441.0     decreasing  2020-12-26 14:00:00 461.0     decreasing  2020-12-27 08:00:00 536.0     no trend  2020-12-27 08:00:00 547.0     no trend  2020-12-27 08:00:00 484.0     no trend  2020-12-27 08:00:00 497.0     no trend  2020-12-27 14:00:00 491.0     no trend  2020-12-27 14:00:00 512.0     no trend  2020-12-27 14:00:00 529.0     no trend  2020-12-27 14:00:00 436.0     no trend  

Is there anyway I could it?

https://stackoverflow.com/questions/66848566/adding-column-with-values-from-one-dataframe-to-another-based-on-same-datetime March 29, 2021 at 11:55AM