Page size issue PDF creation of barcodes using reportlab

Question

Okay i created a script today that takes an item# or any number for that purpose to generate a barcode. Now i wanted to print 60 same barcodes in 4 columns, that would make it a matrix of (15 X 4) only making it easy to understand. Now i successfully achieved it with a custom sized page (900*850) and fitted in 15 rows and 4 columns of barcodes generated by reportlab code128.

Here is the code:

from reportlab.graphics.barcode import code128
from reportlab.lib.units import mm
from reportlab.pdfgen import canvas

#----------------------------------------------------------------------#
def createBarCodes():
    codeName = "NOT_C17"

    c = canvas.Canvas(codeName+".pdf")
    c.setPageSize((900, 850))

    barcode_value = codeName
    barcode128 = code128.Code128(
                            barcode_value,
                            barHeight=20,
                            barWidth=1.05,
                            fontSize=15,
                            humanReadable = True
                        )

    x = 15 * mm
    for i in range(4):
        y = 275 * mm
        i=0
        while i < 15:
            barcode128.drawOn(c, x, y)
            y = y - 18 * mm
            i+=1
        x=x+(70*mm)
    c.save()

if __name__ == "__main__":
    createBarCodes()

A file generated by this script

The issue is that now I am restricted to using only US Letter size and no other custom size. I tried few variations but none worked.

Tries:

from reportlab.lib.pagesizes import letter
c = canvas.Canvas(codeName+".pdf", pagesize=letter)

barcode_value = codeName
barcode128 = code128.Code128(
                          barcode_value,
                          barHeight=16.7564*mm,
                          barWidth=44.45*mm,
                          fontSize=15,
                          humanReadable = True
                     )

x = 7.526 * mm
for i in range(4):
    y = 265.524 * mm
    i=0
    while i < 15:
        barcode128.drawOn(c, x, y)
        y = y - 18 * mm
        i+=1
        break
    x=x+(70*mm)
    break
c.save()

and here is the required format that it must fit in. Would be nice to have to help.

Answer 1

You code requires a lot of improvement

1. Use the letter size from reportlab.lib.pagesizes import letter

2. Set your margins and other variables as specified in the document :

    margin_x = 7.526 margin_y = 13.876 padding_x = 7.526 font_size = 15 width, height = letter 

3. Calculate the total size of the generated codebar

    bars_width = (float(width-margin_x*2)-3*padding_x)/4 bars_height = float(height-margin_y*2)/15 

4. The width value passed to the function Code128 is the width of a single bar within the codebar and not the whole codebar, you should keep this value below 1.1

    bar_height = bars_height - font_size bar_width = 1 

5. your loops would be better this way :

    for i in range(0,4): for j in range(0,15): x = margin_x + i * (bars_width+padding_x) y = margin_y + j * bars_height barcode128.drawOn(c, x , y) 

6. this is the final script :

    from reportlab.graphics.barcode import code128 from reportlab.lib.units import mm from reportlab.pdfgen import canvas from reportlab.lib.pagesizes import letter #----------------------------------------------------------------------# def createBarCodes(): codeName = "NOT_C17" c = canvas.Canvas(codeName+".pdf",pagesize=letter) margin_x = 7.526 margin_y = 13.876 padding_x = 7.526 font_size = 15 width, height = letter extra_padding = 20 bars_width = (float(width-margin_x*2)-3*padding_x)/4 bars_height = float(height-margin_y*2)/15 bar_height = bars_height - font_size #For alphanumeric values, the total number of bars is calculated as: #total = (11*string_length+35) bar_width = (bars_width-extra_padding)/(len(codeName)*11+35) barcode_value = codeName barcode128 = code128.Code128( barcode_value, barHeight=bar_height, barWidth=bar_width, humanReadable = True ) for i in range(0,4): for j in range(0,15): x = margin_x + i * (bars_width+padding_x) y = margin_y + j * bars_height barcode128.drawOn(c, x , y) c.save() if __name__ == "__main__": createBarCodes()