Python QRCode Encode, Decode, Webcam Decode, ZBar

import subprocess
import os
import time
import shutil
import hashlib
import zbar
import Image

class QR(object):
    #use these for custom data formats eg. url, phone number, VCARD
    data_encode = {
        'text' : lambda s: str(s),
        'url' : lambda s: s.startswith('[url]http://[/url]') and s or '[url]http://[/url]' + s
    }

    def __init__(
        self, pixel_size=3, level='L', margin_size=4,
        data_type='text', data='NULL', filename=None
    ):
        self.pixel_size = pixel_size
        self.level = level
        self.margin_size = margin_size
        self.data_type = data_type
        self.data = data
        #get a temp directory
        self.directory = os.path.join('/tmp', 'qr-%f' % time.time())
        self.filename = filename
        os.makedirs(self.directory)

    def data_to_string(self):
        return self.__class__.data_encode[self.data_type](self.data)

    def get_tmp_file(self):
        return os.path.join(
            self.directory,
            #filename is hash of data
            hashlib.sha256(self.data_to_string()).hexdigest() + '.png'
        )

    def encode(self, filename=None):
        self.filename = filename or self.get_tmp_file()
        if not self.filename.endswith('.png'):
            self.filename += '.png'
        return subprocess.Popen([
            'qrencode',
            '-o', self.filename,
            '-s', str(self.pixel_size),
            '-m', str(self.margin_size),
            '-l', self.level,
            self.data_to_string()
        ]).wait()

    def decode(self, filename=None):
        self.filename = filename or self.filename
        if self.filename:
            scanner = zbar.ImageScanner()
            # configure the reader
            scanner.parse_config('enable')
            # obtain image data
            pil = Image.open(self.filename).convert('L')
            width, height = pil.size
            raw = pil.tostring()
            # wrap image data
            image = zbar.Image(width, height, 'Y800', raw)
            # scan the image for barcodes
            scanner.scan(image)
            # extract results
            for symbol in image:
                pass
            # clean up
            del(image)
            self.data = symbol.data
            self.data_type = 'text'
            return True
        else:
            return False

    def decode_webcam(self, callback=lambda s:None, device='/dev/video0'):
        # create a Processor
        proc = zbar.Processor()

        # configure the Processor
        proc.parse_config('enable')

        # initialize the Processor
        proc.init(device)

        # setup a callback
        def my_handler(proc, image, closure):
            # extract results
            for symbol in image:
                if not symbol.count:
                    self.data = symbol.data
                    self.data_type = 'text'
                    callback(symbol.data)

        proc.set_data_handler(my_handler)
        # enable the preview window
        proc.visible = True

        # initiate scanning
        proc.active = True
        try:
            proc.user_wait()
            return self.data
        except zbar.WindowClosed:
            pass

    def destroy(self):
        shutil.rmtree(self.directory)

if __name__ == '__main__':
    # Kodlama Encode
    # myCode = QR(data='Hüseyin ÖZDEMİR', pixel_size=10)
    # myCode.encode('test.png')
    # Decode dosyadan png
    #myCode = QR(filename='test.png')
    #if myCode.decode():
    #    print myCode.data
    #    print myCode.data_type
    #    print myCode.data_to_string()
    #Decoding WebCam
    myCode = QR()
    print myCode.decode_webcam()