TypeError: ord() expected string of length

[chenxinye]

It is found that code with the problem:

ts = np.sin(7np.linspace(0,41.8*np.pi,2400))
ts = np.array(ts)
ts -= np.median(ts)
ts *= len(ts)/norm(ts,1)

TOL = .333
abba = ABBA.ABBA(tol=TOL, norm=1);
pieces = abba.compress(ts)
polyg = abba.inverse_compress(ts[0], pieces)
polyg = np.array(polyg)

string, centers = abba.digitize_incremental(pieces)
print('Polygon now represented by the string', string) # output: " Polygon now represented by the string [0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2]"

approx = abba.inverse_transform(string, centers, ts[0]) # TypeError: ord() expected string of length 1, but int found