barcode test

import barcode
from barcode.writer import ImageWriter
from cStringIO import StringIO
from PIL import ImageFont
import os

PATH = os.path.dirname(os.path.abspath(__file__))
FONT = os.path.join(PATH, 'DejaVuSansMono.ttf')

def mm2px(mm, dpi=300):
    return (mm * dpi) / 25.4

class MyImageWriter(ImageWriter):
    def calculate_size(self, modules_per_line, number_of_lines, dpi=300):
        width = 2 * self.quiet_zone + modules_per_line * self.module_width
        height = 1.0 + self.module_height * number_of_lines
        if self.text:
            height += (self.font_size + self.text_distance) / 3

        return int(mm2px(width, dpi)), int(mm2px(height, dpi))

    def _paint_text(self, xpos, ypos):
        # this should hopefully align your font to the left side of the bar code:
        xpos = self.quiet_zone
        pos = (mm2px(xpos, self.dpi), mm2px(ypos, self.dpi))
        font = ImageFont.truetype(FONT, self.font_size)
        self._draw.text(pos, self.text, font=font, fill=self.foreground)

i = StringIO()
bc_factory = barcode.get_barcode_class('upca')
bc_factory.default_writer_options['quiet_zone'] = 1.0
bc_factory.default_writer_options['text_distance'] = 1.0
bc_factory.default_writer_options['module_height'] = 10.0
bc_factory.default_writer_options['module_width'] = 0.3
bc_factory.default_writer_options['font_size'] = 46

bc = bc_factory('12345678910', writer=MyImageWriter())
bc.write(i)

f = file('barcode.png', 'w')
f.write(i.getvalue())
f.close()
i.close()