Element-wise string concatenation in numpy

Question

Is this a bug?

import numpy as np
a1=np.array([\'a\',\'b\'])
a2=np.array([\'E\',\'F\'])

In [20]: add(a1,a2)
Out[20]: NotImplemented

I am t

Answer 1

Another solution is to convert string arrays into arrays of python of objects so that str.add is called:

>>> import numpy as np
>>> a = np.array(['a', 'b', 'c', 'd'], dtype=np.object)   
>>> print a+a
array(['aa', 'bb', 'cc', 'dd'], dtype=object)

This is not that slow (less than twice as slow as adding integer arrays).