How to convert an array of strings to an array of floats in numpy?

Well, if you’re reading the data in as a list, just do np.array(map(float, list_of_strings)) (or equivalently, use a list comprehension). (In Python 3, you’ll need to call list on the map return value if you use map, since map returns an iterator now.)

However, if it’s already a numpy array of strings, there’s a better way. Use astype().

import numpy as np
x = np.array(['1.1', '2.2', '3.3'])
y = x.astype(np.float)