Fixing Plotly Chart Deprecation Warnings In Streamlit
Hey there, fellow Streamlit enthusiasts! Ever run into a mysterious deprecation warning when using st.plotly_chart, even when you're pretty sure you're following the documentation? You're not alone! It seems like some recent updates have introduced a bit of a head-scratcher, specifically when trying to control the width of your Plotly charts using the width="content" parameter. Let's dive into what's going on and how we can get things back to smooth sailing.
Understanding the `st.plotly_chart` Deprecation Warning
So, the core of the issue lies with how Streamlit handles arguments passed to st.plotly_chart. Previously, you might have used the use_container_width argument, but the documentation now points towards using width and height directly. That makes perfect sense, right? You want to control the dimensions of your visualizations. However, it appears that even when you're diligently using the documented parameters like width="content", a deprecation warning related to variable keyword arguments (kwargs) is popping up. This is a bit confusing because you're not explicitly passing any unusual keyword arguments; you're just using the ones Streamlit intends for you to use!
This warning specifically states: "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." The tricky part is that when you set width="content", Streamlit might be internally interpreting this as a variable keyword argument that's triggering the warning, even though it's a documented and intended way to adjust your chart's size. It's like the system is flagging something that it shouldn't be, based on your clear and correct usage. This can be particularly irksome because it adds noise to your console output and might make you question if you're doing something wrong when, in fact, you're following the established guidelines. The expectation is that when you use a parameter as described in the official Streamlit documentation, you shouldn't be greeted with a deprecation notice, especially one that suggests using a different mechanism when the current one is supposed to be valid.
This behavior is especially noticeable in versions like Streamlit 1.50.0. The good news is that this seems to be a regression, meaning it likely worked as expected in prior versions. The development team is aware of this and is working to iron out these kinks. The introduction of changes related to how kwargs are handled is a common part of software evolution, aiming to make the API cleaner and more robust. However, sometimes these changes can inadvertently affect existing, valid use cases. The goal is to ensure that the warning system accurately identifies actual deprecations rather than flagging legitimate parameter usage. So, while it's a minor annoyance for now, understanding the context helps us appreciate the ongoing efforts to refine the Streamlit library.
Reproducible Example and Steps to Reproduce
To make sure we're all on the same page, let's look at the code that triggers this warning. It's surprisingly simple, which is often the case with these kinds of issues.
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")
As you can see, we're creating a basic Plotly figure and then displaying it using st.plotly_chart. The key here is the width="content" argument. When you run this code in a Streamlit environment (version 1.50.0 in this case, on macOS with Python 3.14.2 and Chrome), you'll see the deprecation warning appear in your console, even though width is a documented parameter for controlling the chart's display size within its container. The steps to reproduce are straightforward: simply run this Python script using Streamlit.
The expected behavior, as stated in the issue, is that using width="content" should not result in a deprecation warning. The argument is intended to make the chart responsive to its container's width, a common and useful feature for web applications. The current behavior, however, is that the warning surfaces, suggesting that this usage is somehow problematic or about to be removed. This inconsistency between expected functionality and observed behavior is what we're aiming to resolve. It highlights a need for refinement in how Streamlit processes and validates arguments passed to its components, ensuring that user experience isn't hindered by misleading warnings.
Why This Matters: Smooth User Experience
It might seem like a small thing, but these kinds of warnings can have a ripple effect. Firstly, they can be distracting for developers. When you see a warning, your instinct is to fix it. If the warning is misleading, it wastes time and mental energy as you try to figure out what you're doing wrong, potentially leading you down a rabbit hole of debugging or documentation searching. This is particularly true when the warning pertains to something as fundamental as setting the width of a chart.
Secondly, it can undermine confidence in the library. If users start seeing warnings for things that appear to be standard usage, they might become hesitant to adopt new features or even rely on existing ones, fearing that breaking changes are imminent and unpredictable. A clean console output is often a sign of a healthy and well-maintained project, and these unexpected warnings detract from that.
Moreover, for those deploying Streamlit applications, seeing these warnings in production logs can be concerning. It might lead stakeholders or end-users to believe the application is unstable or built on shaky foundations, even if the functionality is perfectly fine. Addressing these issues ensures a more professional and reliable presentation of your Streamlit projects. The goal is to provide a seamless development and user experience, and that includes minimizing unnecessary or incorrect warnings that could sow confusion.
The underlying cause appears to be related to recent changes in Streamlit's argument handling, specifically concerning how it manages kwargs. While the intention behind these changes is likely to improve the API's design and prevent misuse of arbitrary keyword arguments, it seems to have had an unintended consequence on the st.plotly_chart function when specific, documented parameters like width are used. The fix involves ensuring that Streamlit correctly identifies and allows the use of these documented parameters without triggering the general kwargs deprecation warning. This is a crucial step in maintaining the library's usability and developer trust.
Looking Ahead: Resolution and Best Practices
The good news is that this issue has been acknowledged, and it's likely that a fix will be incorporated into a future Streamlit release. The Streamlit team is generally very responsive to bug reports and community feedback, which is one of the strengths of using an open-source project. Keep an eye on the official Streamlit GitHub repository for updates on this particular issue. In the meantime, while this warning might persist, you can generally ignore it if your charts are rendering correctly and you understand that it's a known quirk rather than a critical error.
As a best practice, it's always a good idea to stay updated with the latest Streamlit releases. Patches and minor versions often include fixes for issues like these. Additionally, when working with Plotly charts in Streamlit, familiarize yourself with the `config` argument. While width and height are for overall dimensions, the `config` dictionary is where you'll pass more fine-grained Plotly-specific configurations, such as `scrollZoom`, `displayModeBar`, or other Plotly.js options. This is the recommended way to handle Plotly configurations that aren't directly mapped to Streamlit arguments, and it aligns with the advice given in the deprecation warning.
For instance, if you wanted to control the display of the mode bar, you would do it like this:
st.plotly_chart(fig, config={
'displayModeBar': False
})
This approach keeps your Plotly-specific settings neatly organized within the `config` dictionary, separating them from Streamlit's layout and display parameters. While it doesn't directly solve the width="content" warning, it's a good practice to adopt for managing Plotly features within Streamlit. Understanding these distinctions helps in writing cleaner, more maintainable Streamlit applications. The evolution of libraries like Streamlit means that APIs change, and adapting to these changes while maintaining functionality is key to leveraging the full power of the tools we use.
In conclusion, the width="content" deprecation warning in st.plotly_chart is a known issue that is likely to be resolved in an upcoming release. By understanding the context, using the provided reproducible code, and adopting best practices for argument handling, developers can navigate this minor hurdle effectively. We look forward to a future Streamlit update that smooths out this particular rough edge, ensuring a more streamlined experience for everyone.
For more information on Streamlit and interactive plotting, you might find these resources helpful:
