Convert string to numpy array

Question

Input:

mystr = "100110" 

Desired output numpy array:

mynumpy == np.array([1, 0, 0, 1, 1, 0]) 

I have tried:

np.fromstring(mystr, dtype=int, sep='') 

but the problem is I can't split my string to every digit of it, so numpy takes it as an one number. Any idea how to convert my string to numpy array?

Answer 1

list may help you do that.

import numpy as np  mystr = "100110" print np.array(list(mystr)) # ['1' '0' '0' '1' '1' '0'] 

If you want to get numbers instead of string:

print np.array(list(mystr), dtype=int) # [1 0 0 1 1 0] 

Answer 2

You could read them as ASCII characters then subtract 48 (the ASCII value of 0). This should be the fastest way for large strings.

>>> np.fromstring("100110", np.int8) - 48 array([1, 0, 0, 1, 1, 0], dtype=int8) 

Alternatively, you could convert the string to a list of integers first:

>>> np.array(map(int, "100110")) array([1, 0, 0, 1, 1, 0]) 

Edit: I did some quick timing and the first method is over 100x faster than converting it to a list first.