Python Barcode Generation -

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i'm using elaphe package python generate ean-13 barcode images. package installed source using tar file found @ https://pypi.python.org/pypi/elaphe.

when run code:

barcode_image_path = "/tmp/"  def create_barcode_image(product_barcode):      path = barcode_image_path + product_barcode + '.png'      img = barcode('ean13', product_barcode,                    options=dict(includetext=true, height=0.4), margin=1)     img.save(path, 'png')      return path

from python interpreter seems work perfectly. correct barcode generated path specify. when run apache using web.py web framework receive error:

traceback (most recent call last):   ...      img_path = create_barcode_image(barcode)    file "/var/www/py/documents/barcode_images.py", line 27, in create_barcode_image      img.save(path, 'png')    file "/usr/local/lib/python2.7/dist-packages/pil/image.py", line 1406, in save      self.load()    file "/usr/local/lib/python2.7/dist-packages/pil/epsimageplugin.py", line 283, in load      self.im = ghostscript(self.tile, self.size, self.fp)    file "/usr/local/lib/python2.7/dist-packages/pil/epsimageplugin.py", line 75, in ghostscript      raise ioerror("gs failed (status %d)" % status)  ioerror: gs failed (status 256)

does know might causing error or how go debugging it?

add in debug statements can walk through:

import sys  barcode_image_path = "/tmp/"  def create_barcode_image(product_barcode):      print >> sys.stderr, "product_barcode: %s" % product_barcode      path = barcode_image_path + product_barcode + '.png'      print >> sys.stderr, "path: %s" % path      img = barcode('ean13', product_barcode,                    options=dict(includetext=true, height=0.4), margin=1)      print >> sys.stderr, "img data: %s" % img.tostring()      img.save(path, 'png')      print >> sys.stderr, "saved %s" % path      return path

then in shell:

$ tail -f /var/log/httpd/error.log # or wherever put

you're looking for: first: output of "product_barcode: ...". that's not blank. if is, problem lies elsewhere, maybe in server config. output of "img data: ...". it's png , not blank. if it's blank, problem lies ghostscript installation.

this rudimentary way of debugging, , feel small projects easy throw in debug statements rather messing around debugger, can difficult set properly.


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