qr code generator in python

This page is mainly about qr code generator in python

OK, so as part of the need to catalogue all my retro computing gear, I wanted some kind of asset management system. I'm working with the Northwest Computer Museum as well, and they are developing an app to scan QR codes and link them to their asset management systen.

Perquisites

Python

Pillow image manipulation library with

> pip install pillow

Python library, qrcode with

> pip install qrcode

Generate a sequence of codes using Python list comprehension.

There are various ways that you can do this but, by far the simplest is with a list comprehension. Here are some of my favourites.

Numerical codes

>>> [i for i in range(100)]

Numerical codes, left padded

>>> [str(i).zfill(8) for i in range(100)]

Hexadecimal codes

>>> [str(hex(i))[2:].zfill(8) for i in range(100)]

Hexadecimal codes, left padded

>>> [str(hex(i))[2:].upper().zfill(len(str(hex(upper))[2:]))+suffix for i in range(lower,upper+1)]

The Script

Probably a bit more complicated than it needs to be, but that's the story of my life.

import random
import os
import qrcode
import time
import csv

def validate(msg,options=[]):
    valid = False
    while not valid:
        value = input(msg)
        if (len(options) > 0):
            if value in options:
                return value
            else:
                print('Not valid choice. Try again.')
        else:
            return value

if __name__ == "__main__":

    # Get parameters
    choice_list = validate('Input - (l)ist or (g)enerate : ',['l','g'])
    if choice_list == 'g':        
        codetype = validate('Type of code - (n)umerical or (h)ex : ',['n','h'])
        padding = validate('Left pad (y/n) : ',['y','n'])
        lower = int(input('Lower (int) : '))
        valid = False
        while not valid:
            upper = int(input('Upper (int) : '))
            if upper >= lower:
                valid = True
            else:
                print('Upper can\t be less than lower. Try again.')
            
        prefix = input('Prefix : ')
        suffix = input('Suffix : ')
        # Define generators
        generators = {
            'ny':'[prefix+str(i)+suffix for i in range(lower,upper+1)]',
            'ny':'[prefix+str(i).zfill(len(str(upper)))+suffix for i in range(lower,upper+1)]',
            'hn':'[prefix+str(hex(i))[2:].upper()+suffix for i in range(lower,upper+1)]',
            'hy':'[prefix+str(hex(i))[2:].upper().zfill(len(str(hex(upper))[2:]))+suffix for i in range(lower,upper+1)]',
            }
        codes = eval(generators[codetype+padding])

    else: # choice_list must be l
        valid = False
        while not valid:
            filename = input('Filename : ')
            if os.path.isfile(filename):
                handle = open(filename,'r')
                codes = handle.readlines()
                handle.close()
                for i in range(len(codes)):
                    codes[i] = codes[i].rstrip('\n')
                valid = True
            else:
                print('File not found. Try again...')

    directory = 'codes'
    size = int(input('Side length (pixels) : '))

    # Clear directory
    print('Warning - all files in \''+directory+'\' will be deleted...')
    input('Press ENTER if you are sure...')

    files_to_delete = os.listdir(directory)
    for file in files_to_delete:
        full_path = os.path.abspath(directory+'\\'+file)
        if os.path.isfile(full_path):
            os.unlink(full_path)

    files = [['code','picture']]
    for code in codes:
        print('Generating QR code for \'{0}\'...'.format(code))
        qr = qrcode.QRCode(
            version = 1,
            error_correction=qrcode.constants.ERROR_CORRECT_M,
            box_size = 5,
            border = 0
            )
        qr.add_data(code)
        qr.make()
        img = qr.make_image()
        img = img.resize((size,size))
        path = os.path.abspath(directory)+'\\'+str(time.time()).replace('.','')+'.png'
        img.save(path)
        files.append([code,path])
        
    csv.sequence2csv(files,'list.csv')

Last modified: October 5th, 2021

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qr code generator in python

Perquisites

The Script