How to use numpy with 'None' value in Python?

Question

I\'d like to calculate the mean of an array in Python in this form:

Matrice = [1, 2, None]

I\'d just like to have my None valu

Answer 1

You might also be able to kludge with values like NaN or Inf.

In [1]: array([1, 2, None])
Out[1]: array([1, 2, None], dtype=object)

In [2]: array([1, 2, NaN])
Out[2]: array([  1.,   2.,  NaN])

Actually, it might not even be a kludge. Wikipedia says:

NaNs may be used to represent missing values in computations.

Actually, this doesn't work for the mean() function, though, so nevermind. :)

In [20]: mean([1, 2, NaN])
Out[20]: nan