Reportlab and Barcodes

[Josh]

Hi All,

I need someone to explain to me how to output a Code39 barcode to a
Reportlab PDF. As far as I can tell, there is no means to do this with
the Canvas object, and the demo that is included with the libraries is
using the platypus Frame to place the barcode on the form. I do not
wish to use this method. I'm guessing that it needs to be placed on the
form as some type of graphic. It's obviously not going to work with the
drawText method. Any ideas?

Thanks

Josh

 

[Neil Benn]

Hi All,

I need someone to explain to me how to output a Code39 barcode to a
Reportlab PDF. As far as I can tell, there is no means to do this with
the Canvas object, and the demo that is included with the libraries is
using the platypus Frame to place the barcode on the form. I do not
wish to use this method. I'm guessing that it needs to be placed on the
form as some type of graphic. It's obviously not going to work with the
drawText method. Any ideas?

Thanks

Josh

Hello,

Code39 isn't that complicated a barcode symbology to work
with. What you can do is to write some code which can encode a Code39
barcode from a string into a simple graphic. I used to have the
official spec for the barcode but that was in an old job. You can get
the official spec from AIM - you'll have to pay for it but it's not
much. Although beware about the Narrow:Width ratio if you're gonna try
and scan the barcode after printing it out - try and get hold of a
crappy scanner (I got stung by using a good scanner before in the past).

Cheers,

Neil

--

Neil Benn
Senior Automation Engineer
Cenix BioScience
BioInnovations Zentrum
Tatzberg 46
D-01307
Dresden
Germany

Tel : +49 (0)351 4173 154
e-mail : (e-mail address removed)
Cenix Website : http://www.cenix-bioscience.com

 

[Josh]

Benji,

I have used those very same fonts before and they work great, but I'm
trying to get away with using straight Python to accomplish this,
especially since the program will most likely be used on both Linux and
Windows.

Josh

 

[Benji York]

I need someone to explain to me how to output a Code39 barcode to a
Reportlab PDF.

This may not help you directly, but I've made use of it in the past: a
very nice and totally free 3 of 9 TrueType font.

http://www.barcodesinc.com/free-barcode-font/

 

[Josh]

One of the users on the Reportlabs mailing list was kinda enough to
offer me the solution.. A simple call to the drawOn function, e.g.:

bc = code39.Standard39("123",xdim = .015*inch)
x = 6*inch
y = -5*inch
bc.drawOn(canvas,x,y)

 

[Damjan]

One of the users on the Reportlabs mailing list was kinda enough to

offer me the solution.. A simple call to the drawOn function, e.g.:

bc = code39.Standard39("123",xdim = .015*inch)

whats code39 in this example?

 

[Jaime Wyant]

That looks cleaner than mine. I had to do this ->

# Register the barcode true-type-font
# Don't want to push the font out to everyone in the office...
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
pdfmetrics.registerFont( TTFont( 'barcode',
r'c:\inetpub\wwwroot\barcode\fre3of9x.ttf'))

# 'c' is the canvas
c.setFont( "barcode", 40 )
c.drawString( x * inch, y * inch, text )

jw

 

[Josh]

Damjan,

Code39 here refers to part of the Barcode Extensions available to
Reportlabs. It can be imported as such

from reportlab.extensions.barcode import code39

Josh

 

[czl]

How to get human readable barcode

Hello All,
how to get human readable barcode?
I have found example of code: two.pairlist.net/pipermail/reportlab-users/2008-November/007685.html

from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import A4
from reportlab.lib.units import mm
from reportlab.graphics.barcode import code39

TEXT = "TEST01L4"

c=canvas.Canvas("barcode.pdf",pagesize=A4)
barcode=code39.Standard39(TEXT, barWidth=0.423*mm, barHeight=10*mm,
ratio=2.75, humanReadable=True)
barcode.drawOn(c,50*mm,50*mm)
c.showPage()
c.save()

After runing I have got:

Traceback (most recent call last):
File "E:\reportlab-barcode\1.py", line 11, in <module>
barcode.drawOn(c,50*mm,50*mm)
File "C:\Python25\lib\site-packages\reportlab\platypus\flowables.py", line 102
, in drawOn
self._drawOn(canvas)
File "C:\Python25\lib\site-packages\reportlab\platypus\flowables.py", line 86,
in _drawOn
self.draw()#this is the bit you overload
File "C:\Python25\lib\site-packages\reportlab\graphics\barcode\common.py", lin
e 146, in draw
self.drawHumanReadable()
File "C:\Python25\lib\site-packages\reportlab\graphics\barcode\common.py", lin
e 164, in drawHumanReadable
self.annotate(x+width/2.,-y,s,fontName,fontSize)
File "C:\Python25\lib\site-packages\reportlab\graphics\barcode\common.py", lin
e 176, in annotate
getattr(canv,func)(text,x,y)
File "C:\Python25\lib\site-packages\reportlab\pdfgen\canvas.py", line 1217, in
drawCentredString
width = self.stringWidth(text, self._fontname, self._fontsize)
File "C:\Python25\lib\site-packages\reportlab\pdfgen\canvas.py", line 1320, in
stringWidth
(fontSize,self._fontsize)[fontSize is None])
File "C:\work\reportlab-2.2\src\rl_addons\rl_accel\_rl_accel.c", line 1104, in
stringWidthU
File "C:\work\reportlab-2.2\src\rl_addons\rl_accel\_rl_accel.c", line 1147, in
_instanceStringWidthU
AttributeError: decode

How to execute abovesaid code?