Combine time(Object type) and Date(Datetime64[ns])

Question

My data set contains multiple columns of sales-related data. I have ORDEREDDATE and TIMESTAMP in the DataFrame. I want to replace the column with ORDEREDTIME in the dataset.

ORDEREDDATE  TIMESTAMP
 2018-05-13   21:54:45   
 2017-08-24   5:44:25      
 2018-06-01   6:58:15   

my expected output is

          ORDEREDTIME
     2018-05-13 21:54:45   
     2017-08-24 05:44:25      
     2018-06-01 06:58:15    

in a single column.

Answer 1

IIUC

pd.to_datetime(df[['ORDEREDDATE','TIMESTAMP']].astype(str).agg(' '.join,1))
Out[19]: 
0   2018-05-13 21:54:45
1   2017-08-24 05:44:25
2   2018-06-01 06:58:15
dtype: datetime64[ns]
df['ORDEREDTIME'] = pd.to_datetime(df.astype(str).agg(' '.join,1))