NaN and Inf in Python

NaN.py

#Q: How do you represent NaN of Inf in Python?
#A: Call float(x) with x as either the string "NaN" or "Inf" to create a NaN or Inf value.
nan = float('NaN')
inf = float('Inf')

#Q: How to check NaN of Inf value
#A: math.isnan(x), math.isinf(x)
import math
math.isnan(nan)
>>> True
math.isnan(inf)
>>> False
math.isinf(inf)
>>> True