how to zscore normalize pandas column with nans?

Question

I have a pandas dataframe with a column of real values that I want to zscore normalize:

>> a
array([    nan,  0.0767,  0.4383,  0.7866,  0.8091,  0.195         


        

Answer 1

I am not sure since when this parameter exists, because I have not been working with python for long. But you can simply use the parameter nan_policy = 'omit' and nans are ignored in the calculation:

a = np.array([np.nan,  0.0767,  0.4383,  0.7866,  0.8091,  0.1954,  0.6307, 0.6599, 0.1065,  0.0508])
ZScore_a = stats.zscore(a,nan_policy='omit')

print(ZScore_a)
[nan -1.14832945  0.07147776  1.24641928  1.3223199  -0.74791154
0.72051236  0.81901449 -1.0478033  -1.23569949]