Use np.savetxt to save a numpy structured array containing string and float

Question

I have a numpy structured array that contains a string and a float. I want to keep this structured array as it is in the csv file. A simplified version of my procedure is as follows.

    structured_array = np.zeros((1,), dtype=[('string','a20'),('float','f8')])
    structured_array['string'] = 'string'
    structured_array['float'] = 0.0
    np.savetxt('foo.csv', structured_array, delimiter=',',fmt='%s,%f')

I would expect string,0.000000in foo.csv, but it gives me b'string',0.000000where this quotation mark came from and this b? How can I get rid of it?

I can use readline()and get rid of it manually, but is there any smart way to do this.

Many thanks.

Answer 1

Line 1087 in savetxt(... \ lib \ site-packages \ numpy \ lib \ npio.py) has

for row in X:
    fh.write(asbytes(format % tuple(row) + newline))

, (, b). , .