How to generate QR codes in Python?
May 21, 2025 pm 09:39 PMYou can use the qrcode library to generate QR code in Python. 1. Install the qrcode library: pip install qrcode[pil]. 2. Create a QRCode object and add data: qr = qrcode.QRCode(version=1, error_correction=qrcode.constants.ERROR_CORRECT_L, box_size=10, border=4); qr.add_data('https://example.com'); qr.make(fit=True). 3. Generate and save the image: img = qr.make_image(fill_color="black", back_color="white"); img.save("example_qr.png").
Generating QR codes in Python is fun and practical, especially when it is necessary to quickly generate scanable QR codes. Let me introduce in detail how to implement this function and some points that need to be paid attention to in actual applications.
Generating QR codes in Python mainly relies on a library called qrcode
. This library is powerful and easy to use and can quickly generate various types of QR codes. You may be wondering, why use Python to generate QR codes? Because Python has a rich ecosystem and many libraries for processing images and data, this makes generating QR codes simple and efficient.
To start using the qrcode
library, you need to install it first. This can be done easily with the pip
command:
pip install qrcode[pil]
Here I recommend the installation pil
(Python Imaging Library) option because it allows us to perform more customization operations on the generated QR code, such as resizing, adding colors, etc.
OK, after installing the library, we can start generating the QR code. Here is a simple example showing how to generate a QR code containing a URL:
import qrcode # Create a QRCode object qr = qrcode.QRCode( version=1, error_correction=qrcode.constants.ERROR_CORRECT_L, box_size=10, border=4, ) # Add data to QRCode object qr.add_data('https://example.com') qr.make(fit=True) # Create an Image object img = qr.make_image(fill_color="black", back_color="white") # Save the image img.save("example_qr.png")
This snippet shows how to generate a QR code containing the URL and save it as a PNG file. Let's take a look at some details in the process:
- Version : The version of the QR code determines its size and storage capacity. Version 1 is the smallest, version 40 is the largest.
- Error correction level (error_correction) : QR code supports four error correction levels: L (7%), M (15%), Q (25%), and H (30%). Choosing the right level ensures that the QR code can be scanned even if partially damaged.
- Box size (box_size) and border : These parameters control the visual performance of the QR code.
In practical applications, you may encounter some common problems, such as the generated QR code cannot be scanned, or more information needs to be embedded in the QR code. Here are some suggestions and experiences:
- Improve error correction level : If you are worried that QR code will be damaged, increasing error correction level can increase its readability.
- Resize : Sometimes the generated QR code is too small to scan, and adjusting
box_size
appropriately can solve this problem. - Embed more information : QR codes can contain text, URL, contact information, etc., and adjust the data format as needed.
Here are some suggestions for performance optimization and best practices:
- Batch Generation : If you need to generate a large amount of QR code, consider using batch scripts to improve efficiency.
- Caching : If the content of the QR code does not change frequently, it can be cached after generation to avoid repeated generation.
- Custom style : Use the
pil
option to add colors, logos, etc. to make the QR code more personalized, but be careful not to affect the scanning effect.
Overall, the qrcode
library in Python provides a simple and powerful way to generate QR codes. By placing the parameters rationally and applying best practices, you can generate QR codes that meet your needs. Hope these sharing will help you better use this tool in your actual project.
The above is the detailed content of How to generate QR codes in Python?. For more information, please follow other related articles on the PHP Chinese website!

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