generates QR codes with letter and number pairs, saves to a PDF

gen_qr_codes.py

from PIL import Image
from PIL import ImageDraw
from qrcode.main import QRCode
from qrcode.constants import ERROR_CORRECT_L
from PIL import ImageFont
from typing import Sequence, Generator, TypeVar
import math

_T = TypeVar("_T")


def grouper(iterable: Sequence[_T], n: int) -> Generator[Sequence[_T], None, None]:
    """
    given a iterable, yield that iterable back in chunks of size n. last item will be any size.
    """
    for i in range(math.ceil(len(iterable) / n)):
        yield iterable[i * n : i * n + n]


biggerFont = ImageFont.truetype("font.ttf", 500)
smallerFont = ImageFont.truetype("font.ttf", 250)
smallestFont = ImageFont.truetype("font.ttf", 150)
requests = []

aisles = {"MD1": 25, "GR1": 25, "GM1": 20, "FT1": 17, "FT2": 20, "BK1": 30}
aisles = {"A": 8, "B": 8, "C": 8, "D": 8, "E": 14, "F": 12, "G": 12, "H": 12, "I": 16, "J": 10}


for letter, count in aisles.items():  # 10 rows of steel
    for number in range(count):  # 16 sections max
        requests.append((letter, number + 1))

images = []
for index, group in enumerate(grouper(requests, 4)):

    # Create an image object with the desired dimensions
    img = Image.new("RGB", (2200, 1700), color=(255, 255, 255))

    # 2200 / 2 -> 1100 per verticle
    # 1700 / 2 -> 850 per horizontal
    print(f"{index=}, {group=}")
    for i in range(2):
        for j in range(2):
            if len(group) == 0:
                break
            this_group = group.pop(0)
            letter = str(this_group[0])
            number = str(this_group[1])
            qr = QRCode(
                version=1,
                error_correction=ERROR_CORRECT_L,
                box_size=50,
                border=0,
            )
            qr.add_data(f"{letter}-{number}")
            qr.make(fit=True)
            qr_img = qr.make_image(fill_color="black", back_color="white")
            img.paste(
                qr_img.resize((750, 750)),
                ((j * 1100 + 50), (i * 850) + 50),
            )
            if len(letter) == 3:
                ImageDraw.Draw(img).text(((j * 1100) + 810, (i * 850) + 250), letter, font=smallestFont, fill="black")
            else:
                ImageDraw.Draw(img).text(((j * 1100) + 810, (i * 850) - 100), letter, font=biggerFont, fill="black")
            if len(number) == 2:
                ImageDraw.Draw(img).text(((j * 1100) + 810, (i * 850) + 450), number, font=smallerFont, fill="black")
            else:
                ImageDraw.Draw(img).text(((j * 1100) + 810, (i * 850) + 300), number, font=biggerFont, fill="black")

    # Save the image
    images.append(img)
    img.save(f"out_{index}.jpg")


images[0].save("out_all.pdf", save_all=True, append_images=images[1:])