Basic QR Code Generator — plotnine

A QR (Quick Response) code visualization that encodes text or URL data into a square matrix barcode pattern. QR codes are two-dimensional barcodes that store information in a grid of black and white squares, readable by smartphones and dedicated scanners. This visualization is useful for generating scannable codes for quick data sharing and mobile access.

Basic QR Code Generator rendered with plotnine

Renders

Python source (plotnine)

""" anyplot.ai
qrcode-basic: Basic QR Code Generator
Library: plotnine 0.15.7 | Python 3.13.14
Quality: 88/100 | Created: 2026-06-24
"""

import os
import sys


_script_dir = os.path.dirname(os.path.abspath(__file__))
sys.path = [p for p in sys.path if p and os.path.abspath(p) != _script_dir]

import pandas as pd
import qrcode
import qrcode.constants
from plotnine import (
    aes,
    coord_fixed,
    element_rect,
    element_text,
    geom_tile,
    ggplot,
    labs,
    scale_fill_manual,
    theme,
    theme_void,
)


# Theme tokens
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"

# QR module colors — dark on light bg / light on dark bg for scannability
MODULE_ON = "#1A1A17" if THEME == "light" else "#F0EFE8"
MODULE_OFF = PAGE_BG  # quiet zone matches page background

# Data — encode anyplot.ai URL with error correction level M (15%)
URL = "https://anyplot.ai"
qr = qrcode.QRCode(error_correction=qrcode.constants.ERROR_CORRECT_M, box_size=1, border=4)
qr.add_data(URL)
qr.make(fit=True)

matrix = qr.get_matrix()
n = len(matrix)

rows = []
for r, row in enumerate(matrix):
    for c, val in enumerate(row):
        rows.append({"x": c, "y": n - 1 - r, "module": "on" if val else "off"})
df = pd.DataFrame(rows)

# Plot
title = "qrcode-basic · python · plotnine · anyplot.ai"

plot = (
    ggplot(df, aes(x="x", y="y", fill="module"))
    + geom_tile(width=1.02, height=1.02)
    + scale_fill_manual(values={"on": MODULE_ON, "off": MODULE_OFF})
    + coord_fixed()
    + labs(title=title, subtitle=URL)
    + theme_void()
    + theme(
        figure_size=(6, 6),
        plot_background=element_rect(fill=PAGE_BG, color=PAGE_BG),
        panel_background=element_rect(fill=PAGE_BG),
        plot_title=element_text(color=INK, size=12, ha="center"),
        plot_subtitle=element_text(color=INK_SOFT, size=9, ha="center"),
        legend_position="none",
    )
)

# Save
plot.save(f"plot-{THEME}.png", dpi=400, width=6, height=6, units="in")

Part of Basic QR Code Generator on anyplot.ai.

Basic QR Code Generator — plotnine

Renders

Python source (plotnine)

Other implementations