Streamlit migration Guide

[MarcSkovMadsen]

Closes #5016

You can preview the guides here

• Index
• Getting Started
• panes
• layouts
• widgets
• templates
• activity
• interactivity
• caching
• session_state
• multipage_apps

I really hope that this will help our users migrate. And that it will inspire us to improve our framework like in #5019.

Todo

• Create the content
• Check some Streamlit guides that no key concepts have been forgotten
  • Streamlit main concepts
• Improve the guide and test all examples
• Record and add .png ang .gif where needed.
• Finalize Implement support for reactive generator functions #5019
• Get Review and improve
  • Please check toctree, grids, cards and similar. I don't know how to build this effectively. Takes 10 mins for me to figure out how. Takes 30-60 mins for me to build the documentation.
  • Please consider whether the Panel code examples can be considered best practice
  • Please consider whether we are missing some functionality in Panel to make the migration easy.
• Philipp: Fix pn.cache only caches for a session.  #5109
• Convert absolute links to relative links.
  • Please help me. I tried but failed. I need help to do this. Because of the way the documentation is built I cannot always discover or test the right relative links.
• Andrew offered to contribute session state example with dynamic layouts.
• List improvement ideas in List of improvements inspired by Streamlit Migration Guide #5028
• Philipp: Move assets like .png and .gif files to the cdn
• Refactor into standalone guides

Maybe one day in another PR

Describe migrating

• Forms
• Custom components

[MarcSkovMadsen]

I see this PR surving multiple purposes.

The primary purpose is to provide

• a resource that can help users migrate from Streamlit to Panel. This was motivated by a request for help by a user on Discourse.

But it also indirectly provides

• an alternative introduction to Panel for users already are familiar with Streamlit
• a means of comparing Streamlit and Panel on a more detailed level
• a means of getting inspiration from Streamlit that can be used to improve our framework.

If someone thinks a "migration guide" would be seen as "agressive" (?) we could re-purpose the guide and focus on one or more of the indirect uses. If all together we don't think this fits into our documentation I could publish this as a personal blog post.

Personally I see a guide for users that comes with a Streamlit background as a helpful, natural thing to add and not aggressive at all. Streamlit is a benchmark and many users will better understand things in that context.

As context I would also plan to contribute a similar guide for Gradio one day as I and Panel could learn a lot from that one as well. And it would help users that have learned the Gradio way of building data apps to use our framework.

Please let me know (@maximlt , @philippjfr, @droumis ) if you think this guide should be repurposed or published as a personal blog post. Thanks.

[philippjfr]

Personally I have no concerns here, we're not claiming Streamlit sucks we are just making it easier for existing users to translate concepts they already know if they find streamlit limiting.

[maximlt]

Same, migration guides are going to be very helpful to users coming from other libraries.

[codecov]

Codecov Report

Merging #5027 (7ffd59d) into main (eaf5853) will increase coverage by 11.19%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             main    #5027       +/-   ##
===========================================
+ Coverage   72.62%   83.82%   +11.19%     
===========================================
  Files         274      274               
  Lines       39583    39584        +1     
===========================================
+ Hits        28749    33181     +4432     
+ Misses      10834     6403     -4431     

Flag	Coverage Δ
ui-tests	40.56% <ø> (?)
unitexamples-tests	73.76% <ø> (+1.14%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
panel/io/cache.py	84.29% <ø> (ø)
panel/io/state.py	73.45% <ø> (+2.93%)	⬆️
panel/pane/base.py	85.82% <ø> (+0.26%)	⬆️
panel/widgets/button.py	87.06% <ø> (ø)

... and 71 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[MarcSkovMadsen]

Assets

Hello World

Outputs

Inputs

Layouts

(Note: I could not find st.row, st.spacer, margin or similar functionality to layout this nicely with Streamlit)

Templates

Interactivity Basic Example

Show Activity

Interactivity Multiple Updates Example

Interactivity Multiple Outputs Example

Session Cache

Session State

[philippjfr]

If this is to stay in the how_to guide then we need to break this up into individual sections.

[MarcSkovMadsen]

If this is to stay in the how_to guide then we need to break this up into individual sections.

Do you mean the guide is too big and does not fit the concept of a how-to guide?

[philippjfr]

Do you mean the guide is too big and does not fit the concept of a how-to guide?

Yep, but I think it could very cleanly be split up into a whole how-to section with various sub-guides. What do you think?

[MarcSkovMadsen]

It can probably be done but

1. Do you want that. It will take up a lot of "space" compared to rest of guides.

2. Will it work when we add migration guides for other frameworks?

[ahuang11]

Just a thought; the benefit of it being on one page is the ability to CTRL+F

[philippjfr]

It'd be organized just like the other how-to guides, each card on https://panel.holoviz.org/how_to/index.html corresponds to a how-to section with multiple smaller guides.

[MarcSkovMadsen]

So at https://panel.holoviz.org/how_to/index.html there would be a section called Migration Guides

One card would be Streamlit. Another Gradio.

If you click Streamlit you would navigate to another page with several cards each representing a section in the Streamlit Migration guide?

[philippjfr]

Exactly right.

[MarcSkovMadsen]

I'll start working on this.

[philippjfr]

Really appreciate this, this is looking really great!

[MarcSkovMadsen]

Migration to standalone guides is done. I've done a first review. Probably needs one or more reviews to make sure everything makes sense as individual guides and together.

I will try to do it before I leave for holiday later today. Otherwise feel free to do it and finalize 😄

[MarcSkovMadsen]

Is it possible to get this one deployed to the dev site @philippjfr . It would help a lot to see the rendered version.

[philippjfr]

Is it possible to get this one deployed to the dev site @philippjfr . It would help a lot to see the rendered version.

You can always do this yourself:

[MarcSkovMadsen]

I just triggered it. After that I discovered you also triggered a docs build an hour ago @philippjfr . But the dev site seems not to be up?

[MarcSkovMadsen]

Looking at the docs I can see they failed due to PIL.

[philippjfr]

Yeah something seems to have gone wrong when migrating from pyviz-dev to holoviz-dev

[philippjfr]

I'm merging and fixing followup issues in separate PRs. Thank you so much @MarcSkovMadsen and thanks for your review/contributions @ahuang11!

[MarcSkovMadsen]

And thanks for generator functions and more. Our Api just got much better.