python - How do I remove all zero elements from a NumPy array?

Question

I have a rank-1 numpy.array of which I want to make a boxplot. However, I want to exclude all values equal to zero in the array. Currently, I solved this by looping the array and copy the value to a new array if not equal to zero. However, as the array consists of 86 000 000 values and I have to do this multiple times, this takes a lot of patience.

Is there a more intelligent way to do this?

question from:https://stackoverflow.com/questions/5927180/how-do-i-remove-all-zero-elements-from-a-numpy-array

Answer 1

For a NumPy array a, you can use

a[a != 0]

to extract the values not equal to zero.