[FIXED] finding and replacing 'nan' with a number

Issue

I want to replace number 3 instead of all 'nan' in array. this is my code:

train= train.replace("nan",int(3))

But nothing changes in my array. Could u please guide me?

Solution

>>> import math
>>> train = [10, float('NaN'), 20, float('NaN'), 30]
>>> train = [3 if math.isnan(x) else x for x in train]
>>> train
[10, 3, 20, 3, 30]

Answered By - Raymond Hettinger