if condition not meet, leave blank python code

Question

how should we write the code that tell python to leave empty cell in dataframe when the condition is not meet?

I tries " " like excel but it does not work. I tried 'space' also not work either.

eg. np.where((df['Adj Close']> df['signal']), 1, 'what should be the sign here? ' )

Thanks in advance.

I am expecting the code to return blank cell in pandas dataframe when I run the code.

Answer 1

If need empty numeric value use missing value NaN:

np.where(df['Adj Close']> df['signal'], 1, np.nan)