Introduction to Python qrcode Library

We must have seen QR codes in real life. QR codes are now used everywhere. QR codes are those square-shaped, black-and-white patterns we see on products, posters, business cards, and even Wi-Fi routers. These are used to store information that can be quickly scanned and read by a smartphone or a QR code scanner. It can be used for websites, products, etc. QR codes store information in a scannable format, which can be anything from URLs to text. The qrcode module in Python is used to create QR codes with just a few lines of code. This module is very easy for generating QR codes for our projects, apps, or even personal use.

What is Python-qrcode?

The qrcode is a Python library that allows us to generate QR codes using a few lines of code. QR codes are a type of two-dimensional barcode that can store a variety of data, such as URLs, text, or contact information. We can create QR codes that store URLs, text, or any other data we want to make easily accessible. The qrcode is useful in web development, marketing, and various digital applications.

Key Features of Python-qrcode

There are different features present in qrcode code library of Python. These features make the generation of QR easy and flexible.

• Simple to Use - This library can generate QR codes with just a few lines of code.
• Customizable - We can change the size, colors, and error correction levels of our QR codes.
• Data Versatility - We can add text, URLs, or any other data to our QR codes.
• Image Saving - We can save QR codes as image files in various formats like PNG or JPEG.

Installing Python-qrcode via pip

Before using the qrcode library we need to install it. We can do this using pip, Python's package installer.

pip install qrcode[pil]

Here PIL is necessary for handling images.

Basic Usage

After installing the qrcode library, we can start generating QR codes with just a few lines of code. Now let's see some basic examples

1. Generating a Simple QR Code

Below is given how we can generate a basic QR code that contains a simple message:

2. Saving QR Codes as Image Files

We can easily save the generated QR code as an image file:

Output: Scan the qrcode to see data

3. Customizing QR Code Size and Border

We can customize the size and border of your QR code by passing parameters to the QRCode object. Below is example:

Output:

Advanced Features of qrcode

The qrcode library has several advanced features that make it even more powerful.

1. Adding Data to QR Codes (Text, URLs, etc.)

We can add different types of data to your QR code, not just plain text. For example, here’s how to encode a URL:

Output:

2. Customizing QR Code Colors

We can change the color of the QR code and the background color:

Output:

3. Optimizing QR Code Generation

The qrcode library allows us to optimize QR code generation by controlling the error correction level. The higher error correction levels make the QR code easier to scan even when it is partially damaged. It also increase the size of the QR code.

Error Correction Levels

There are four levels of error correction:

• L (Low): Recovers 7% of data.
• M (Medium): Recovers 15% of data.
• Q (Quartile): Recovers 25% of data.
• H (High): Recovers 30% of data.

We can choose the appropriate level of error correction, depending on our needs.

Controlling QR Code Complexity

If the QR code generated by us becomes too complex such as, if it contains a lot of data, then it might be difficult to scan. We can control the complexity by modifying the version parameter, which determines the size of the QR code.

Use Cases

We can use QR codes which can be used for different real-life applications. Below are some of examples:

• Creating QR Codes for Business Cards - We can generate a QR code that contains our contact information.
• Generating QR Codes for Wi-Fi Access - We can create a QR code that is used to automatically connects the user to a Wi-Fi network when scanned.
• QR Codes for Event Tickets and Payment Systems - QR codes are widely used in event management and payment systems. They can be scanned at the entrance of an event.

Full Example Code

Now, we are going to create a QR code that stores a URL. We first create an instance of the QRCode class. We can customize the size, error correction level, box size, and border thickness. We add the data to the QR code using qr.add_data(data). qr.make(fit=True) makes sure that the QR code is optimized for the data size. The make_image() function generates the actual QR code image, where we can specify colors we want.

Output

Conclusion

The qrcode in Python is a powerful and easy-to-use library which helps in generating QR codes. We can generate qrcode in Python using few lines of code. The qrcode module in Python is used used for generating qr codes. We can create customized QR codes for various applications. We can create qr code for personal use or even just for fun.