Modernize portfolio optimizer

[jtao1]

Modernizing an example checklist

Preliminary checks

• [x] Look for open PRs and issues that reference the project you are updating. It is possible previous unmerged work in PR could be re-used to modernize the project. Comment on these PRs and issues when appropriate, hopefully we should be able to close some of them after your modernizing work.

Change ‘anaconda-project.yml’ to use the latest workable version of packages

• [x] Pin python=3.11
• [x] Remove the upper pin (e.g. hvplot<0.9 to hvplot, panel>=0.12,<1.0 to panel>=0.12) of all other dependencies. Removing the upper pins of dependencies could necessitate code revisions in the notebooks to address any errors encountered in the updated environment. Should complexities or extensive time requirements arise, document issues for team discussion on whether to re-pin specific packages or explore other solutions.
• [x] Add/update the lower pin of all other dependencies (e.g. hvplot to hvplot>=0.9.2, hvplot>=0.8 to hvplot>=0.9.2). Usually, the new/updated lower pin of a dependency will be the version resolved after anaconda prepare has been run. Execute !conda list in a notebook, or anaconda run conda list in the terminal, to display the version of each dependency installed in the environment. Adjusting the lower pin helps ensure that the locks produced for each platform (linux-64, win-64, osx-64, osx-arm64) rely on the tested dependencies and not on some older versions.
• [x] If one of the channels include conda-forge or pyviz, ask Maxime if it can be removed

Plot API updates (discussed on a per-example basis)

• [x] Generally, try to replace HoloViews usage with hvPlot. At a certain point of complexity, such as with the use of ‘.select’, it might be better to stick with HoloViews. Additional examples of ‘complexity boundaries’ should be documented in this document.
• [x] Almost always, try to replace the use of datashade with rasterize (read this page). Essentially, rasterize allows Bokeh to handle the colormapping instead of Datashader.

Interactivity API updates (discussed on a per-example basis)

• [x] Remove all pn.interact usage
• [x] Avoid .param.watch() usage. This is pretty low-level and verbose approach and should not be used in Examples unless required, or an Example is specifically trying to demo its usage in an advanced workflow.
• [x] Prefer using pn.bind(). Read this page for explanation.
• [x] For apps built using a class approach, when they create a view() method and call it directly, update the class by inheriting from pn.viewable.Viewer and replace view() by __panel__(). Here is an example.

Panel App updates (discussed on a per-example basis)

• [x] If the project doesn’t at any point create a Panel app at all, consider creating one. It can be as simple as wrapping a plot in pn.Column, or more complicated to incorporate widgets, etc. Make the final app .servable().
• [x] If the project creates an app in a notebook but doesn’t deploy it (i.e. there is no command: dashboard declaration in the anaconda-project.yml file), try adding it.
• [x] If the project already deploys an app but doesn’t wrap it in a nice template, consider wrapping it in a template.
• [x] If the project deploys an app wrapped in a template, customize the template a little so all the apps don’t look similar (e.g. change the header background color). This doesn’t need to be discussed.
• [x] Comment start If you are building the application in a single cell, you can construct a template explicitly, like template = pn.template.BootstrampTemplate, but if building up an app across multiple cells, it is probably cleaner to declare the template at the top with pn.extension(template='bootstrap'). See how to guide on setting a template.

General code quality updates

• [x] If the notebook disables warnings (e.g. with warnings.simplefilter(‘ignore’) somewhere at the start of the notebook, remove this line. Try to update the code to remove the warnings, if any. If updating the code to remove the warnings is taking significant amount of time and effort, bring it up for discussion and we may decide to disable warnings again.

Text content

• [x] Edit the text content anywhere and everywhere that it can be improved for clarity.
• [x] Check the links are valid, and update old links (e.g. http -> https, xyz.pyviz.org -> xyz.holoviz.org)
• [x] Remove instructions to install packages inside an example

Visual appearance - Example

• [x] Check that the titles/headings make sense and are succinct.
• [x] Check that the text content blocks are easily readable; revise into additional paragraphs if needed.
• [x] Check that the code blocks are easily readable; revise as needed. (e.g. add spaces after commas in a list if there are none, wrap long lines, etc.)
• [x] Check image and plot sizes. If possible, making them responsive is highly recommended.
• [x] Check the appearance on a smartphone (check Google to see how to adapt the appearance of your browser to display pages as if they were seen from a smartphone, this is usually done via the web developer tools). This is not a top priority for all examples, but if there are a few easy and straightforward changes to make that can improve the experience, let’s do it.
• [x] Check the updated notebook with the original notebook

Visual appearance - Gallery

• [x] Check the thumbnail is visually appealing
• [x] Check the project title is well formatted (e.g. Ml Annotators to ML Annotators), if not, add/update the examples_config.title field in anaconda-project.yml
• [x] Check the project description is appropriate, if not, update the description field in anaconda-project.yml

Workflow (after you have made the changes above)

• [x] Run successfully doit validate:<projectname>
• [x] Run successfully doit test:<projectname>
• [x] Run successfully doit doc_one –name <projectname>. It’s better if the project notebook(s) is saved with its outputs (but be sure to clear outputs before committing to the examples repo!) when building the docs. Then open this file in your browser ./builtdocs/index.html and check how the site looks.
• [x] If you’re happy with all the above, open a PR. Reminder, clear notebook outputs before pushing to the PR.

[github-actions[bot]]

Your changes were successfully integrated in the dev site, make sure to review the pages of the projects you touched before merging this PR: https://holoviz-dev.github.io/examples/. You can also download an archive of the site from the workflow summary page which comes in handy when your dev site built was overriden by another PR (we have a single dev site!).

[maximlt]

I have a suggestion about the notebook being a little dry and lacking context. Maybe you could throw the notebook content at ChatGPT and ask for it to add some brief explanations about the underlying analysis. That's just a suggestion, so feel free to ignore it if you don't feel like it. I think though that ChatGPT could do a good job at this, given this is I believe a very common kind of analysis.

[github-actions[bot]]

Your changes were successfully integrated in the dev site, make sure to review the pages of the projects you touched before merging this PR: https://holoviz-dev.github.io/examples/. You can also download an archive of the site from the workflow summary page which comes in handy when your dev site built was overriden by another PR (we have a single dev site!).

[jbednar]

It's possible we'll try to migrate to pn.rx

Is there anyone who is arguing for keeping it hvplot.interactive? pn.rx seems like the obvious thing to do, unless someone is very convincingly arguing otherwise.

[ahuang11]

Was helping Jason with rx and it felt like rx was a bit magical / unintuitive to me.

Also, we weren't sure how to separate out the widgets to better lay out the dashboard, unlike pn.Param.

I'm -1 on using rx since I think it could just potentially confuse new users with all the ways to do something--at least until there are more examples and docs on how to use it, i.e. do this/not that, good patterns/anti-patterns.

from io import BytesIO
import pandas as pd
import panel as pn
pn.extension()

@pn.cache
def get_stocks(data):
    if data is None:
        stock_file = 'https://datasets.holoviz.org/stocks/v1/stocks.csv'
    else:
        stock_file = BytesIO(data)
    return pd.read_csv(stock_file, index_col='Date', parse_dates=True)

file_input = pn.widgets.FileInput(sizing_mode='stretch_width')

stocks = pn.rx(get_stocks)(file_input)

selector = pn.widgets.MultiSelect(
    name='Select stocks', sizing_mode='stretch_width',
    options=stocks.columns.to_list()
)

selected_stocks = stocks.rx.pipe(
    lambda df, cols: df[cols] if cols else df, selector
)

pn.Column(selected_stocks)

Lastly, upon printing rx objects, it raises an error https://github.com/holoviz/param/issues/939

[ahuang11]

Ok I just realized there's a section in Panel about rx; I was too focused on the param docs.

To split the widget + column, you need to wrap it in the corresponding pane; personally I'd prefer a method to call to do so, e.g. selected_stocks.get_pane()

from io import BytesIO
import pandas as pd
import panel as pn
pn.extension()

@pn.cache
def get_stocks(data):
    if data is None:
        stock_file = 'https://datasets.holoviz.org/stocks/v1/stocks.csv'
    else:
        stock_file = BytesIO(data)
    return pd.read_csv(stock_file, index_col='Date', parse_dates=True)

file_input = pn.widgets.FileInput(sizing_mode='stretch_width')

stocks = pn.rx(get_stocks)(file_input)

selector = pn.widgets.MultiSelect(
    name='Select stocks', sizing_mode='stretch_width',
    options=stocks.columns.to_list()
)

selected_stocks = stocks.rx.pipe(
    lambda df, cols: df[cols] if cols else df, selector
)

pn.Column(
    pn.Row(file_input, selector),
    pn.pane.DataFrame(selected_stocks),
)

[github-actions[bot]]

Your changes were successfully integrated in the dev site, make sure to review the pages of the projects you touched before merging this PR: https://holoviz-dev.github.io/examples/. You can also download an archive of the site from the workflow summary page which comes in handy when your dev site built was overriden by another PR (we have a single dev site!).

[github-actions[bot]]

Your changes were successfully integrated in the dev site, make sure to review the pages of the projects you touched before merging this PR: https://holoviz-dev.github.io/examples/. You can also download an archive of the site from the workflow summary page which comes in handy when your dev site built was overriden by another PR (we have a single dev site!).

[jbednar]

@ahuang11 : Ok I just realized there's a section in Panel about rx; I was too focused on the param docs.

Can you please make a PR on Param putting in an explicit link to the Panel rx docs wherever you would have found them? Right now it only links to the main Panel site, but pointing directly to Panel rx info would presumably prevent others from having the same experience you did.

[github-actions[bot]]

Your changes were successfully integrated in the dev site, make sure to review the pages of the projects you touched before merging this PR: https://holoviz-dev.github.io/examples/. You can also download an archive of the site from the workflow summary page which comes in handy when your dev site built was overriden by another PR (we have a single dev site!).

[github-actions[bot]]

Your changes were successfully integrated in the dev site, make sure to review the pages of the projects you touched before merging this PR: https://holoviz-dev.github.io/examples/. You can also download an archive of the site from the workflow summary page which comes in handy when your dev site built was overriden by another PR (we have a single dev site!).

[github-actions[bot]]

Your changes were successfully integrated in the dev site, make sure to review the pages of the projects you touched before merging this PR: https://holoviz-dev.github.io/examples/. You can also download an archive of the site from the workflow summary page which comes in handy when your dev site built was overriden by another PR (we have a single dev site!).

[droumis]

I made a lot of changes. There were still many issues: headings, grammatical, organizational, textual. In the future, the PRs need to be further along prior to asking for a final review.

[github-actions[bot]]

Your changes were successfully integrated in the dev site, make sure to review the pages of the projects you touched before merging this PR: https://holoviz-dev.github.io/examples/. You can also download an archive of the site from the workflow summary page which comes in handy when your dev site built was overriden by another PR (we have a single dev site!).