Pandas DataFrame Replace NaT with None

Question

I have been struggling with this question for a long while, and I tried different methods.

I have a simple DataFrame as shown,

I can use code to rep

Answer 1

Make the column type as str first

 dfTest2.InvoiceDate =  dfTest2.InvoiceDate.astype(str)

then compare it directly with "NaT" and replace with None

dfTest2.InvoiceDate = dfTest2.InvoiceDate.apply(lambda x : None if x=="NaT" else x)