pythonpandasexcel-automation

why date-time is automatically changed to the object datatype?

Need to convert object type to Date-time and use that converted date-time is unknowingly changed to the object again while filtering. 

msft['Tested On'] = pd.to_datetime(msft['Tested On'])
msft['Tested On'].dt.date
df = msft[msft['Tested On'] == '2018-02-02']

Actual result: TypeError: 'NoneType' object is not subscriptable

Expected result: Need to display the filtered list with the other rows and columns also

Solution

  • I think you need to_datetime and if first digit is day, add parameter dayfirst=True:

    print (msft)
  Title plan     run   status           Tested On
0     A   P0      P0   Passed  11/08/2018 8:42 AM
1     B   P0      P0   Failed  12/08/2018 8:42 AM
2     C    -  Canary   Passed  10/08/2018 8:42 AM
3     D    -  Sanity  Blocked  11/08/2018 8:42 AM

msft['Tested On'] = pd.to_datetime(msft['Tested On'], dayfirst=True)
print (msft)
  Title plan     run   status           Tested On
0     A   P0      P0   Passed 2018-08-11 08:42:00
1     B   P0      P0   Failed 2018-08-12 08:42:00
2     C    -  Canary   Passed 2018-08-10 08:42:00
3     D    -  Sanity  Blocked 2018-08-11 08:42:00

    Then remove times by dt.floor and compare:

    df = msft[msft['Tested On'].dt.floor('d') == '2018-08-11']
print (df)
  Title plan     run   status           Tested On
0     A   P0      P0   Passed 2018-08-11 08:42:00
3     D    -  Sanity  Blocked 2018-08-11 08:42:00

    Detail:

    print (msft['Tested On'].dt.floor('d'))
0   2018-08-11
1   2018-08-12
2   2018-08-10
3   2018-08-11
Name: Tested On, dtype: datetime64[ns]