Fix: Streamlit Plotly Chart Deprecation Warning

Hey there, data enthusiasts! Ever run into a pesky deprecation warning while using st.plotly_chart in Streamlit, even when you're sure you're playing by the rules? You're not alone, and we're going to dive deep into this issue. This article breaks down the problem, provides a clear example, and offers potential solutions to keep your Streamlit apps running smoothly. We'll explore the core of the plotly_chart kwargs deprecation warning and how it affects your projects.

The Heart of the Matter: st.plotly_chart and Deprecation

Let's get down to brass tacks. The issue revolves around how Streamlit handles keyword arguments (kwargs) in its st.plotly_chart function. Specifically, when you use parameters like width="content" or height, you might encounter a deprecation warning, even if you're not explicitly passing any additional keyword arguments. This is a bit of a head-scratcher, right? The warning indicates that variable keyword arguments are deprecated and will be removed in a future release. Streamlit is encouraging users to use the config argument for Plotly configuration options instead.

This deprecation is triggered by a check within the st.plotly_chart function. If any kwargs are detected, the warning is displayed. The challenge arises because some documented parameters, like width and height, seem to inadvertently trigger this warning, even though they are explicitly supported. This behavior can be confusing and lead to unnecessary warnings in your Streamlit applications.

Understanding the kwargs Warning

The warning message itself is pretty straightforward, but let's break it down further. It's essentially telling you that the way you're passing extra options to st.plotly_chart might change in the future. Streamlit developers are steering users toward a more explicit method of configuring Plotly charts. The intention is to improve code clarity and maintainability. When you encounter this warning, you're not necessarily doing anything wrong, but it signals that your code might need a slight adjustment down the line to stay compatible with future Streamlit versions. This is why understanding and addressing this warning is crucial for ensuring the longevity of your Streamlit applications.

Reproducing the Issue: A Code Example

To really understand the problem, let's look at a concrete example. The following code snippet demonstrates how the deprecation warning appears:

import plotly.graph_objects as go
import streamlit as st

fig = go.Figure()
fig.add_trace(go.Barpolar(r=[1], theta=[0], width=[120]))
fig.update_layout(width=500, height=360)

st.plotly_chart(fig, width="content")

In this example, we create a simple polar bar chart using Plotly. We then use st.plotly_chart to display the chart in our Streamlit app. Notice that we're passing width="content". Even with this simple setup, you're likely to see the deprecation warning, even though width is a documented parameter of st.plotly_chart.

Step-by-Step Reproduction

1. Install necessary libraries: Make sure you have Streamlit and Plotly installed.
2. Copy and paste the code: Put the provided code example into a Python file (e.g., app.py).
3. Run the Streamlit app: Open your terminal and run streamlit run app.py.

You should see the polar bar chart displayed in your Streamlit app, along with the deprecation warning in the console.

Potential Solutions and Workarounds

While there isn't a direct fix for the warning itself (as it's triggered by the internal workings of st.plotly_chart), there are ways to manage it and keep your code clean and forward-compatible.

1. Acknowledge and Monitor: The simplest approach is to acknowledge the warning and keep an eye on updates to Streamlit. The warning suggests that the config argument is the future. So, if your app works as expected, you might choose to ignore the warning for now, but be prepared to update your code when a new Streamlit version is released.
2. Explicit Configuration (Future-Proofing): Start migrating towards using the config argument to set up your Plotly chart options, even though it's not strictly required in this specific scenario. The config argument allows you to pass in Plotly configuration options explicitly. This is the recommended approach for future compatibility and cleaner code. You can use it to control things like the chart's display mode bar, responsiveness, and other interactive features. By adopting this approach, you proactively address the deprecation warning and make your code more robust.
3. Check Streamlit Updates: Keep a close eye on Streamlit's release notes. Developers often provide guidance on how to update your code to align with the latest changes. Make sure that you are using the latest version available.

Deep Dive into config

The config argument is your friend when it comes to the future of st.plotly_chart. It lets you customize your charts in a more structured way. With config, you can specify a wide range of options, such as enabling or disabling the display of the mode bar, controlling the chart's responsiveness, and setting other interactive features. This allows you greater control over how your Plotly charts render within your Streamlit apps. You can find detailed documentation on Plotly's configuration options to help you fine-tune your charts.

Conclusion: Navigating the Deprecation Warning

The st.plotly_chart kwargs deprecation warning might seem like a minor annoyance, but understanding its cause and knowing how to manage it ensures your Streamlit apps remain functional and up-to-date. By understanding the underlying issue and following the suggested solutions, you can keep your Streamlit projects running smoothly and avoid any future compatibility issues. Embrace the config argument and stay informed about Streamlit updates to keep your data visualizations on point!

Key Takeaways:

• The warning arises due to the use of kwargs in st.plotly_chart.
• Explicitly using documented parameters like width or height can trigger the warning.
• Acknowledge the warning and monitor Streamlit updates.
• Consider using the config argument for future compatibility.

Hopefully, this detailed exploration has shed some light on this deprecation warning and given you the tools to tackle it head-on. Happy coding!