Streamlit Plotly_chart Deprecation Warning Fix

Streamlit's plotly_chart Deprecation Warning: A Deep Dive

Hey everyone, let's talk about a common hiccup many of us face when working with Streamlit and Plotly: the pesky deprecation warning that pops up when using st.plotly_chart with width="content". It's a real head-scratcher, especially when you're not even intentionally using any extra keyword arguments (kwargs) beyond the documented ones. In this article, we'll break down the issue, explore how to reproduce it, and hopefully, find a solution to keep our Streamlit apps running smoothly. We will use bold, italics, and strong tags to highlight important parts. Let's get started, guys!

The Heart of the Problem: plotly_chart and kwargs

The core of the problem lies within Streamlit's st.plotly_chart function. Specifically, it involves how Streamlit handles keyword arguments when rendering Plotly charts. You see, when you use the width="content" (or even height) parameter, you might inadvertently trigger a deprecation warning related to kwargs. This warning signals that the way certain keyword arguments are handled is changing and will eventually be removed in future Streamlit versions. The current behavior, though, is a bit confusing because the warning appears even when you're only using the documented width and height parameters, and not passing any additional, undocumented kwargs.

Reproducible Code Example: Seeing the Warning in Action

To really understand the issue, let's look at a simple, reproducible code example. This is the beauty of a good bug report: you can create a concise, self-contained piece of code that demonstrates the problem. Here's what the example looks like:

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")

If you run this in your Streamlit app, you'll likely see the deprecation warning. It's a clear indication that something isn't quite right, and it can be a bit alarming, especially if you're not expecting it. The key takeaway is that this warning is triggered by simply specifying the width="content" parameter, without any other extra arguments.

Steps to Reproduce: It's Really That Simple!

The steps to reproduce this issue are incredibly straightforward. All you need to do is:

1. Import the necessary libraries: plotly.graph_objects as go and streamlit as st.
2. Create a Plotly figure (e.g., a go.Figure() object).
3. Add a trace (e.g., go.Barpolar) to your figure. Customize it to your liking, but keep it simple for the sake of the demonstration.
4. Update the layout of your figure, setting desired dimensions (e.g. width and height).
5. Use st.plotly_chart(fig, width="content") to render the chart in Streamlit.

That's it! The deprecation warning should appear. This highlights that the problem is not your code, but a potential internal issue within Streamlit or its interaction with Plotly.

Expected Behavior vs. Current Behavior: A Discrepancy

The expected behavior is that when you use documented parameters like width="content", you shouldn't receive a deprecation warning about kwargs, especially if you're not explicitly using any undocumented arguments. The current behavior, however, shows that the warning is triggered even under these circumstances. This discrepancy creates confusion and suggests a potential bug or misconfiguration in how Streamlit handles these arguments internally.

Is This a Regression? Identifying the Root Cause

Yes, this issue appears to be a regression. In earlier versions of Streamlit, the use of documented parameters like width="content" didn't trigger this warning. This suggests that a change in a recent Streamlit update or a related dependency is the root cause. This information is critical for developers as it helps pinpoint the source of the problem and guides the fix.

Debugging Info: The Tools of the Trade

Providing debug information is crucial for anyone trying to troubleshoot or fix the issue. Here's the debug info for our case:

• Streamlit version: 1.50.0
• Python version: Python 3.14.2
• Operating System: MacOs 26.1
• Browser: Chrome

This information is essential because it gives context to anyone who is trying to figure out what is happening. By giving them the information about the environment, it helps narrow down the problem.

The Road Ahead: Potential Solutions and Workarounds

While the specific solution might require a fix from the Streamlit developers, there are potential workarounds you could try in the meantime:

• Upgrade Streamlit: Sometimes, the issue is resolved in a newer version. Always check for updates.
• Inspect the config argument: The deprecation warning suggests using the config argument instead of kwargs. Experiment with this argument to see if it resolves the issue.
• Check Plotly version: Ensure you have the right version of Plotly. Sometimes version conflicts can create problems.
• Simplify the code: Temporarily remove some of the styling and customizations to see if the error persists. It could be triggered by something specific.

The Final Word: Staying Informed and Helping Out

This deprecation warning is a minor annoyance, but it underscores the importance of staying up-to-date with library versions and paying attention to warnings. By reporting the issue, providing a reproducible example, and offering debugging information, you're helping the community! If the warning keeps appearing, keep an eye on the Streamlit release notes and issue trackers for updates and potential solutions. Keep on coding, and remember, we're all in this together!

This detailed breakdown should give everyone a good understanding of the st.plotly_chart deprecation warning. If you have any further ideas or insights, please share them so that we can have a fruitful conversation.