I am trying to create a new column 'Var' in the following Pandas DataFrame based on values from the other columns. I am encountering issues when dealing with the NaN, NaT.

Data: ( Used apply(pd.to_datetime) on the Date columns at a previous step)

Code:

def program(Flat):
    if Flat['A'] == 'N' :
        return 0
    elif Flat['Date'].isna() :
        return Flat['Age']   1
    elif Flat['C'] < 365 :
        return 1
    elif Flat['C'] >= 365 :
        return math.floor((Flat['C'])/365.25)   1

Flat['Var'] = Flat.apply(program, axis=1)

Error: AttributeError: 'NaTType' object has no attribute 'isna'

Tried running through Anaconda & Python. All same error. Pandas version is 1.3.3.

What is the correct way to detect the NaT type?

CodePudding user response：

"NaT" (for date/time types) and "NaN" are not the same. However, you can use the "isnull" function for both types:

    elif pd.isnull(Flat['Data']):