Streamlit Plotly Chart Warning Fix

Hey everyone! Let's dive into a bit of a head-scratcher that some of you might have run into when working with Streamlit and Plotly. We're talking about the plotly_chart kwargs deprecation warning. It can be a bit confusing, especially when you're just trying to get your awesome charts to display nicely without any pesky warnings popping up. So, what's the deal, guys? Let's break it down.

The Nitty-Gritty: What's Happening with plotly_chart?

So, you're building a cool data visualization app with Streamlit, and you're using st.plotly_chart to display your Plotly figures. All's going well, but then you notice a warning. It's something along the lines of: "Variable keyword arguments for st.plotly_chart have been deprecated and will be removed in a future release. Use the config argument instead to specify Plotly configuration options." Now, this can be a real head-scratcher, especially if you haven't been explicitly passing variable keyword arguments. You might be thinking, "Wait, what kwargs? I'm just using the documented parameters like width='content'!"

This is exactly the crux of the issue. The warning seems to be triggered even when you're using perfectly valid and documented arguments like width='content' or height='content'. It feels like the system is getting a bit confused and throwing a warning where it shouldn't be. This used to work seamlessly in older versions, which makes it feel like a bit of a regression for those of us who rely on these features. We're not trying to do anything fancy or undocumented here; we're just trying to control the size of our charts using the expected parameters.

Let's look at a quick example that demonstrates this:

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")

When you run this code, you'll likely see that deprecation warning pop up, even though width='content' is a standard way to tell Streamlit to adjust the chart's width based on its container. It's a bit frustrating because it muddies the console output and might make you worry if you're doing something wrong. The goal here is pretty straightforward: we want to use st.plotly_chart with arguments like width or height without triggering a warning about deprecated kwargs when we're not actually using them in a deprecated way. It's about keeping our code clean and our Streamlit apps running without unnecessary noise. We're looking for a clean implementation where standard parameters don't accidentally trigger warnings related to a different kind of argument usage.

Why This Warning Matters (Even When It's Misleading)

It's easy to dismiss a deprecation warning, especially if your code still works. However, these warnings are there for a reason. They're signals from the library developers that a certain way of doing things is going to change or be removed in the future. Ignoring them can lead to your code breaking when you eventually update Streamlit or its dependencies.

In this specific case, the warning seems to be a bit overzealous. It's designed to catch users who are passing arbitrary keyword arguments directly to st.plotly_chart that are meant for Plotly's configuration object, rather than using the dedicated config parameter. The idea is to encourage users to pass Plotly-specific configurations through the config dictionary, which is the cleaner and more explicit way to do it. For instance, if you wanted to set Plotly-specific options like scrollZoom or displayModeBar, you'd put them in st.plotly_chart(fig, config={'scrollZoom': True, 'displayModeBar': 'true'}).

However, arguments like width and height when used with st.plotly_chart are not Plotly configuration options; they are Streamlit-specific arguments that control how the chart is displayed within the Streamlit app's layout. They are not meant to be passed into Plotly's internal configuration. So, when the warning fires for width='content', it's essentially misinterpreting a Streamlit layout parameter as a Plotly configuration parameter being passed incorrectly.

This is why it feels like a regression. Users who have been using these width and height parameters in their Streamlit apps are now seeing a warning that doesn't accurately reflect their code's intent. It suggests that perhaps the internal logic that checks for kwargs might be too broad or is not correctly differentiating between Streamlit-specific arguments and Plotly-specific configurations. The desired behavior is that Streamlit's own layout parameters for plotly_chart should not trigger this particular kwargs deprecation warning.

The Expected vs. Current Behavior: A Closer Look

Let's get crystal clear on what we expect to happen versus what's actually happening. According to the Streamlit documentation and common usage patterns, when you use st.plotly_chart, you can pass arguments that control its presentation within your Streamlit app. Arguments like width and height are part of this Streamlit-specific control. For example, setting `width=