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

Question

How to get from ["1.1", "2.2", "3.2"] to [1.1, 2.2, 3.2] in numpy?

Joe Kington · Accepted Answer · 2010-10-06 22:04:11Z

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).

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'], dtype='|S4')
y = x.astype(np.float)

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