Prevent strings being truncated when replacing values in a numpy array

Question

Lets say I have arrays a and b

a = np.array([1,2,3])
b = np.array([\'red\',\'red\',\'red\'])

If I were to apply s

Answer 1

A marginal improvement on your current approach (which is potentially very wasteful in space):

import numpy as np

a = np.array([1,2,3])
b = np.array(['red','red','red'])

replacement = "blue"
b = b.astype('

This accounts for strings already in the array, so the allocated space only increases if the replacement is longer than all existing strings in the array.