Question

I have this class representing my model :

from google.appengine.ext import db

class PuzzleSets(db.Model):
   img = db.BlobProperty(required=True)
   ...

and I want to retrieve that blobproperty. However, I want to retrieve the bytes array and output it to a string. Ex. : “AE214FAA21617772” for a 8 bytes image stored in my blob.

I tried with a blob_reader and some other methods but I always get errors like

UnicodeDecodeError: ‘utf8’ codec can’t decode byte 0x89 in position 0: invalid start byte

or

hex() argument can’t be converted to hex

and such

Anyone can help me get the correct way to do this?
Thanks!

Answer 1

I finally got what I wanted with this sleek line of code :

self.response.out.write(''.join([hex(z)[2:].zfill(2) for z in bytearray(puzzleset_instance.img)]))