Fix for issue #770. Try to convert to float first, and if that fails convert to bytes

[eblis]

Alternatively I see that another method is used further up in the codebase, starting on line 3400:

                all_bytes = True
                for v in ret.tolist():
                    if not isinstance(v, bytes):
                        all_bytes = False
                        break

                if not all_bytes:
                    try:
                        ret = ret.astype("f8")
                    except:
                        if not as_object:
                            ret = np.array(
                                [np.nan if isinstance(v, bytes) else v for v in ret]
                            )

                else:
                    ret = ret.astype(bytes)

We could use this check to see if we need to convert to float or bytes, but I wouldn't iterate over all items if we can help it.

[danielhrisca]

The output array must have a numeric dtype or 'S' dtype.
Mixing bytes and float values would result in an 'O' dtype output array (object dtype).

[danielhrisca]

thank you @eblis