src/streamlit_app.py

import streamlit as st
import qrcode
import io

# Set page title
st.title("QR Code Generator")

# Get user input
url = st.text_input("Enter a URL or text to generate a QR code:")

if url:
    # 1. Generate the QR code object
    # qrcode.make() returns a PIL image (specifically qrcode.image.pil.PilImage)
    img = qrcode.make(url)

    # 2. Create a BytesIO buffer to hold the image data in memory
    buffer = io.BytesIO()

    # 3. Save the image to the buffer in PNG format
    # This resolves the "TypeError: a bytes-like object is required"
    img.save(buffer, format="PNG")

    # 4. Display the image using the buffer
    # "use_container_width=True" resolves the Deprecation Warning
    st.image(
        buffer, 
        caption="Generated QR Code", 
        use_container_width=True
    )
else:
    st.info("Please enter text above to generate a QR code.")