Getting Started With Dash: Easy Data Visualization In Python

Getting Started With Dash: Easy Data Visualization In Python - Part 1/3

Рет қаралды 94,068

Күн бұрын

A very common thing you want to do in Python is visualize your data in a dashboard. Today I show you how to set up data visualization using Plotly Dash in Python in a few easy steps. I'm going to revisit this example in a few weeks to add more features to the dashboard and to improve the design. A big thank you to Mark Todisco for his help with preparing the code example!
The code I worked on in this tutorial is available here: github.com/ArjanCodes/2022-dash.
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👀 Code reviewers:
- Yoriz
- Ryan Laursen
- James Dooley
- Dale Hagglund
🎥 Video edited by Mark Bacskai: / bacskaimark
🔖 Chapters:
0:00 Intro
1:17 Explaining the example
2:41 Introduction to Dash
5:10 Setting up a Dash application
8:02 Adding a dropdown component
13:09 Adding a button to select all nations
14:31 Dash callbacks with inputs and outputs
17:21 Adding a bar chart
20:24 Connecting the dropdown with the bar chart
24:10 Showing a message if no data is selected
25:02 Analysis of the application setup
#arjancodes #softwaredesign #python
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Пікірлер: 154

@ArjanCodes 8 ай бұрын

💡 Get my FREE 7-step guide to help you consistently design great software: arjancodes.com/designguide.

@vigneshmurali1994 Жыл бұрын

As someone who really likes your tutorials and shorts and a patron of this channel. If I can make a suggestion, 1. Whenever you talk about a specific module or a feature it would be better if you should something visual and do a voiceover. This is help people to understand what it is that you are exactly referring to at any point in time. 2. Before diving coding always provide with a good overview which can help people understand what it is that you are trying to do end to end. (Remember you may be knowing stuff beforehand but for the people who are watching you will need to have some context on what you are going to do). Just some friendly suggestions.:) Cheers

@agar.iodestiny8677 Жыл бұрын

Just what I needed. Great video once again, you can't imagine the influence of your videos on a self-taught like me. Your channel is a gold mine, and the content can't be found anywhere on the web. Can't thank you enough for your content. Thank you!!!

@ArjanCodes Жыл бұрын

Thanks, happy you’re enjoying the content!

@kgrileyfyi Жыл бұрын

Dude you really changed my life. Every since you taught me about the importance of python classes with dataclasses. All my sqlalchemy models became serialized with jsonify. I implemented the command pattern to generate pdfs and send invoices and I set up a transaction based accounting system. All your video have transformed my app in such a positive way. It feels like every video you post is a module that can be directly inserted in my app replacing my old code and vastly improving it into a way less coupled system. I just want to thank you because their is none of this stuff out there beside the content you are creating.

@ArjanCodes Жыл бұрын

Hey Kevin, so glad to hear the content has been helpful to you. Keep going, looks like you're killing it!

@luannguyen743 Жыл бұрын

I work with data and really like using Dash. However I have been struggling with structuring a Dash project in a clean way. Thanks for sharing this, Arjan. Just what I needed.

@saitaro Жыл бұрын

Can this thing replace React or Vue for a pythonista? I don't like frontend stuff and wondering if this can save me.

@utica2burn 10 ай бұрын

I have programmed in Python for years, but honestly all new to me to see syntax like "from . import" and "->" in a function definition. Some further studies needed to completely understand this tutorial.

@MarvinAustria1 Жыл бұрын

Love it! First time working with Dash and I love your explanation! Thank you

@edip_c Жыл бұрын

Yet another fantastic video. Love how you make concepts easy to digest. ❤❤ Thanks a lot Arjan!

@ArjanCodes Жыл бұрын

My pleasure ❤

@Plotly Жыл бұрын

Awesome video, @ArjanCodes. Thank you for using Plotly and Dash and for teaching others.

@ArjanCodes Жыл бұрын

Thank you! And happy to promote great tools ☺️.

@carecavoador Жыл бұрын

Uow! This is so powerful and elegant! Thank you so much for this, Arjan.

@ArjanCodes Жыл бұрын

Thanks so much Careca, glad it was helpful!

@liucloud6317 Жыл бұрын

Your tutorials are always clear and concise! Thank you for sharing it, Arjun!

@ArjanCodes Жыл бұрын

Thanks Liu, happy you’re enjoying the content!

@emonymph6911 Жыл бұрын

You earned a sub for actually slowing down for 15sec and explaining the terminology. "So for this we need a callback... A callback is..." Thank you! Most people would never define it. This means we can watch one of your videos and learn everything required to complete the task without having to search for other stuf. It means a lot!

@warrenarmstrong1032 Жыл бұрын

Thank you for covering this topic Arjan!

@ArjanCodes Жыл бұрын

Thanks so much Warren, glad it was helpful!

@izem9652 Жыл бұрын

You can use the query method with f-strings if you want to reference to the 'nations' variable: MEDAL_DATA.query(f"nation in {nations})")

@aflous Жыл бұрын

But why use query in the first place? The most common way I saw for filtering panda' dataframes rely on just using a mask. It's much readable imho

@ArjanCodes Жыл бұрын

We used masks in an earlier version of the code example, and using query resulted in a lot shorter code, especially if you combine multiple filters. It’s also really efficient.

@MaxMustermann-on2gd Жыл бұрын

@@ArjanCodes I also prefer working with the query method. There are just some cases which combine slicing+filtering and can get a bit complicated. Most often such cases require .iloc .. in these instances I often use a mask. Apart from that .query in combination with f-strings or the @-notation is really powerful and I guess more humam readable.

@BPopes Жыл бұрын

Even better (I think) you can use one of the kwargs that query accepts: `MEDAL_DATA.query("nation in @var", local_dict={"var": nations})`. This way your linter won't complain and you can let pandas interpret the variable.

@antoniocarlossegurogonzale2973 Жыл бұрын

Right when I needed this, thank you so much Arjan

@ArjanCodes Жыл бұрын

Thanks so much Antonio, glad it was helpful!

@ronalddebruijn613 Жыл бұрын

Just in time this video! As a retired programmer, I started learning python just for fun. Looking for structure in the python world, I found your channel. It helps a lot. I like your pragmatic approach using classes and functional programming. Just now I started looking at Plotly and Dash. Again looking for structure, again provided by ArjanCodes..

@ArjanCodes Жыл бұрын

Thanks so much Ronald, glad it was helpful!

@zachazares8355 Жыл бұрын

I remember watching this mini-series when it came out & enjoying the content. Now, months later after having made a dashboard used internally at my company, I rewatched & realized so many smelly parts of my code that your design has helped me refactor. Your content is so helpful & practical for learning good philosophies of code after the 1st, 2nd, & countless rewatches. Thank you for your entire channel Arjan!

@ArjanCodes Жыл бұрын

Thank you so much!

@tinylittleanj2 Жыл бұрын

did you use the microsoft Graph sdk or something to authenticate users, or is it just on the local network? I like the idea of being able to switch (mostly for my own satisfaction) people from Power BI over to a python solution. We currently use Azure to authenticate users (and filter the datasets they are getting)...

@user-jd6bm9vm3j 2 ай бұрын

Usually I do not tend to comment on videos but let me thank you for this gift of video!! You cannot imagine how much you helped me understand the way dash works - I am currently studying Data Science and this was great for making my data visualisation project where I analysed US accidents and their distribution over the different states. Thank you Arjan :))

@ArjanCodes 2 ай бұрын

Glad to hear that the video was helpful to you! Thank you for the comment :)

@user-xd5gd4pc9h Жыл бұрын

Looking forward to the 2nd part！

@ArjanCodes Жыл бұрын

It’s coming this Friday ;).

@kantorobo7718 Жыл бұрын

Beste Arjan heel veel succes, dit is een toffe tutorial.

@Jonathan-ex3sl Жыл бұрын

this is great! can't wait for the next video :)

@ArjanCodes Жыл бұрын

Coming soon!

@fennecbesixdouze1794 Жыл бұрын

Please set the path to your interpreter in VS Code so all the code from these third-party libraries isn't highlighted red.

@TimoRJensen Жыл бұрын

@RedShipsofSpainAgain Жыл бұрын

How do you set the path to your interpreter in vs code?

@AugustoGeografo Жыл бұрын

Arjan, thanks for the great carefully designed content. The render function, in your example, gets a def function inside of it. Is there another pattern which can be used there? Making the nested def outside and calling it inside render?

@heirofsam Жыл бұрын

This really helped me a lot, Thanks!

@0lec817 Жыл бұрын

Hi Arjan, thanks for the great video! Just a quick question: Is there a specific reason you use relative imports over absolute imports? My rule of thumb is to always use absolute imports since they are supposedly more clear?

@wayneqwele8847 Жыл бұрын

Yoh great content Arjan !

@ArjanCodes Жыл бұрын

Thanks so much Wayne, glad you liked it!

@marouaneayech 3 күн бұрын

Really awesome video @ArjanCodes, Keep up the great job

@ArjanCodes 3 күн бұрын

Thank you!

@danhintz7306 Жыл бұрын

Great video! Thank you so much! Btw, what color scheme do you use in vscode? It's awesome!

@istvanmeszaros4112 Жыл бұрын

I agree with you about the Python magic. I think it causes more problems in this case than it actually helps. Also without type hinting Dash apps easily become messy. Sometimes even with type hints, just try to change the return HTML instance to html.Span instead of a DIV, not even mypy will complain. (At least this is my current experience) However the lack of types and all this "magic" is very useful in notebooks for data analysts. So probably they should be only used there. FYI, good thing that dash apps also work inside a notebook.

@nicholashemenway2787 9 ай бұрын

Hey Arjan, I love your content and have been following you since you first started on youtube! One question though, why do you find it advantageous to define the callbacks inside of the render functions? As opposed to defining it in a separate module? I haven't seen this style of defining callbacks inside of a render function anywhere else. Thanks!

@Patrick-hl1wp Жыл бұрын

This tutorial is awesome!!

@ArjanCodes Жыл бұрын

Thank you Patrick, glad you liked the video!

@paulstinchcombe1130 Жыл бұрын

fantastic video. Thank you!

@ArjanCodes Жыл бұрын

Thanks Paul, happy you’re enjoying the content!

@text414 Жыл бұрын

Hey @arjancodes, great tutorial. I've just started my dash journey, and this video has proven an invaluable resource. I have one question: why do the layout and component functions take the app as an argument when they contain no direct calls to the app?

@Whatthetrash Жыл бұрын

This is cool, but I often find myself overwhelmed when there are so many new libraries to keep track of. What helped me get comfortable with the possibilities of the base language (Python) is learning the functions and what they do. I feel the same thing is necessary for any library I use. After all, why is a certain function being used as opposed to another function? Does this solve something that cannot be done using 'bare Python', or does it just streamline it? If so, how? All of that helps to make sense of all these imports. For me, knowing the scope of something is very important. All that said, cool video and I look forward to future parts. Cheers! :)

@datacentrico Жыл бұрын

Very cool. Thanks for that.

@ArjanCodes Жыл бұрын

Thanks Thiago, happy you’re enjoying the content!

@esmaelmohamed8209 7 ай бұрын

Arjan ur blessed. No word for me I Thank you very much!!!

@ArjanCodes 7 ай бұрын

I'm glad you've enjoyed the content, Esmael!

@esmaelmohamed8209 7 ай бұрын

@@ArjanCodes Always Arjan, I learn not only from your content, i learn from your word, facial expression, responsibility for your community and how to became selfless person. Arjan your Real Professional. I Salute 🙏 for you and blessed family.

@ryanlong8074 Жыл бұрын

Well said towards the end concerning Python magic.

@ArjanCodes Жыл бұрын

Thanks so much Ryan, glad you liked it!

@omiwa9718 Жыл бұрын

Great tutorial, dash is amazing

@ArjanCodes Жыл бұрын

Thanks so much James, glad you liked it!

@wisanuupatumphun7831 Жыл бұрын

So cool for simple web app to display data nicely!!

@ArjanCodes Жыл бұрын

Thanks so much Wisanu

@anastaha5261 Жыл бұрын

it works perfectly thank you so much

@ArjanCodes Жыл бұрын

Thanks so much, glad the content is helpful!

@ren200758 Жыл бұрын

nice! my first real project is based on Dash! I wish I had seen this video back then to avoid some frustrations. I do have a complaint about typing though. static type check doesn't seem to reliably catch the type of outputs of callbacks and back then something I thought passed in int was actually passed in str.

@jordangigg8631 Жыл бұрын

Heya Arjan, I love your videos and have a suggestion for a future video. I would love to see something involving rate limiting multiple API's concurrently within one program:)

@ArjanCodes Жыл бұрын

Thanks so much, glad you liked it! Thanks for the suggestions, Jordan, I've put it on the list.

@metensis Жыл бұрын

Great video and repo as usual. I am wondering why you are using conda vs pipenv. As pipenv supports multiple python version and simpler config with Pipfile and locking of the config? I found pipenv easier to use. Any thoughts or video in the future? 🙂

@tinylittleanj2 Жыл бұрын

Do you set up an environment when you build these? Or not so much for the tutorials? I don't want to just install everything (in the wild) and was wondering if you have a preferred environment that you use that integrates relatively well with Code.

@PeterSeres Жыл бұрын

Great video. Some feedback though on the video design: going from a dark setup to an all-white webpage is really jarring and would appreciate in newer videos to keep a consistent dark / light theme.

@chillydickie Жыл бұрын

Would it be possible to cover github actions? Perhaps to do automated testing of python scripts since youve covered unit testing before.

@edgeeffect 10 ай бұрын

I come here for Python and software design... but... Dragging a terminal view into a VSCode tab... "woooooah" - "mind blown!" `"terminal.integrated.defaultLocation": "editor",` makes it even better!

@Moncamonca Жыл бұрын

I prefer using boolean masks to filter pandas dataframes, partially for this reason. All objects are referenced as objects explicitly. Although, the query method is convenient in longer chained calls, I have to admit.

@rafaelfelipenovi6308 Жыл бұрын

Very good video, i love dash and r shiny :)

@utica2burn 10 ай бұрын

would you recommend first learning html? coming from a python background and being new to HTML it seems like dash is structured in a way that takes HTML as a prerequisite

@rollinas1 Жыл бұрын

Yes!

@priyesbamne9112 Жыл бұрын

We need an entire python course from you

@ArjanCodes Жыл бұрын

Thanks Priyes! I do have a Python/software design focused online course available here: www.arjancodes.com/mindset

@surajkadel8762 Жыл бұрын

Thank you for this

@ArjanCodes Жыл бұрын

Thanks so much Suraj, glad it was helpful!

@surajkadel8762 Жыл бұрын

I have always been very choosy, when it comes to lectures, instructors or topics. But your videos helped me improve my python coding skills. In the past 6 months, I have seen myself writing better code, credits to you. Hopefully will keep on improving myself. Thank you

@XenoZeduX Жыл бұрын

Dash is awesome, I utilized it to showcase projects in college; I do prefer Streamlit now, there are a few other alternatives as well like Panel

@ArjanCodes Жыл бұрын

Thanks so much Soumendu, glad it was helpful!

@rollinas1 Жыл бұрын

Streamlit is cool, but I can't always figure out how to run it efficiently, without rerunning the unnecessary code every time you interact with GUI

@cerioscha Жыл бұрын

Panel and Holoviews are so handy for rapid development of data science proof of concept dashboards and views.

@williamwatkins6669 Жыл бұрын

What plugins do you use in what I belei5 is vscode for code formatting on svae and auto improts?

@thichquang1011 Жыл бұрын

How would you do to modify the fig data instead of creating a new fig each time the drop-down values change ?

@encoride3312 Жыл бұрын

I need part 3 lol. Will it be styling?

@gtorres94 8 ай бұрын

Hi @ArjanCodes thank you very much for the video. As already stated, it would be great if you could make some pauses and explain some of the code in more detail, otherwise it becomes quite difficult to follow. I have a question for the button callback. How does the app know that the button click refers to that callback and how does the callback know what function to call? I don't see any link bewteen these. Thanks! EDIT: So I finished the video and saw that you mentioned exactly what I was asking. It's indeed quite confusing this "magic" thing of knowing what to do without any kind of reference to the function.

@zenmaster24 Жыл бұрын

in the @app.callback, the input listens to the number of clicks, captured by n_clicks - is this built in to dash as it did not seem to be defined and passed anywhere? excellent and informative tutorial though, as always 👍

@tobyvd Жыл бұрын

This is built-in for the button component. Whenever you click on the button in the UI, it will increment the n_clicks value by one. Then, the callback will activate as the value for n_clicks was changed.

@zenmaster24 Жыл бұрын

@@tobyvd cheers for clearing it up

@SystemSigma_ Жыл бұрын

Great content! Suggestion for next video: how to solve tedious cyclic import error due to type hints imports.. Pleeease :)

@ArjanCodes Жыл бұрын

Thanks for the suggestions, Andrea, I've put it on the list.

@malikrumi1206 Жыл бұрын

@25:00, you create the empty filtered data message and put it in a naked div with no p tag?! I don't claim to be an html/css expert, but I've never seen that before. Is there some unstated part of the Dash framework taking care of that with useful html tag defaults?

@ArjanCodes Жыл бұрын

You don't have to put all text in a paragraph tag in html. I didn't do it here to keep things simple, though it is useful if you want to apply some formatting to the text like changing the font, color or size.

@Antares2390 Жыл бұрын

Did you consider Streamlit rather than Dash as a tool for creating such web apps? Streamlit seems to be clearer for a quick start, and it still provides enough flexibility and functionality.

@alexandrodisla6285 Жыл бұрын

Streamlit lack maturity. Dash, streamlit, shiny for python are made for data applications. Nothing more. Shiny for python is more mature because it stands on shoulders of the shiny framework which was available only with the R language.

@jfsaraceno9265 Жыл бұрын

Great, Charming Data's yt page is awesome too!

@ArjanCodes Жыл бұрын

Thanks so much, glad you liked it!

@rahulkmail Жыл бұрын

Is Dash faster than React or slower than React in loading components ?

@xilan8804 8 ай бұрын

I was wondering if it is possible to have the git hub link? thanks

@RavenGhostwisperer Жыл бұрын

hmm.. trying to understand the scenarios where Dash is better than PyScript (ignoring its current status) - I guess it will depend on the amount of Python code vs HTML?

@sjmarel Жыл бұрын

I also dislike python magic, for it behaves as a sort of obfuscation. Thanks for the vid again!

@ArjanCodes Жыл бұрын

Glad you enjoyed it!

@alexandrodisla6285 Жыл бұрын

Shiny for Python is a good one.

@ArjanCodes Жыл бұрын

Thanks Alexandro, happy you’re enjoying the content!

@NagarajVS-xg9rr 2 ай бұрын

Which IDE is good for creating dashboards with DASH?

@dariuszspiewak5624 Жыл бұрын

I just wonder... How long does it take to learn the ins and outs of, say, Dash and Plotly, to be confident in using them and create something useful. Anyone can comment on this, please? Thanks.

@BiologyIsHot Жыл бұрын

Yeah I don't personally like Pandas attempts at mimicking dplyr. df[df[column] == vals] is great and programmatic enough for me.

@user-wi2en3be9t Жыл бұрын

someone help me, i don't know how to make a template like in this video, i have searched on google but haven't found it

@aliwelchoo Жыл бұрын

Loved this video, especially the layout of components, however I feel like I'd like to keep the callbacks defined elsewhere so the components are reusable without needing other components to exist and also since the callback logic does get complex with needing multiple outputs in the same callback etc

@padraic1983 Жыл бұрын

Can you show us how to integrate a dashboard into a django project?

@matheusvenancio5809 Жыл бұрын

Is there any video where you explain those constructions like "def render(app: Dash) -> html.Div:" Or the name of those constructions, so I can search it Could not understand Thanks

@adamfarquhar1279 Ай бұрын

I'm sure that you've answered this question by now, but these are python type annotations. The simple syntax is `var: type` or `def fun(args) -> type`. The first one indicates that `var` is of type `type` and the second one indicates that `fun` returns an object with type `type`. The type annotations are considered hints rather than declarations. Python doesn't actually do mandatory type checking and the standard cpython doesn't take advantage of the type information. They exist as documentation and the IDEs will use them to help you avoid mistakes in your code. For example, if you a function returns a list and you are adding the result to a float, the IDE can signal that this is likely an error.

@masheroz Жыл бұрын

How can you make this work when you need to upload multiple 100s of megabytes of data?

@williamwatkins6669 Жыл бұрын

Hi, I'm commenting on your latest video as I'm not sure how to reach you otherwise. Could you do a tutorial on what would be the best way to generate documentation for a python project. I see many options. I understand generating docs from comments can be useful, but I'm curious on how the pros do it. Thanks

@ArjanCodes Жыл бұрын

Thanks for the suggestions William!

@nitinkumar7225 Жыл бұрын

Can you cover some topics on Streamlit please?

@ArjanCodes Жыл бұрын

Great suggestion, thank you!

@yliu4093 Жыл бұрын

Thx can you do a video about how to debug dash using vscode thanks

@ArjanCodes Жыл бұрын

Thanks for the suggestions, Y Liu, I've put it on the list.

@shaunakkakade1325 11 ай бұрын

Where did the gold, silver medal numbers for each nation come from?

@imveryhungry112 5 ай бұрын

If dash makes it this easy to write front end aps that generate in react, why would anyone use javascript to do it? Can someone answer that?

@LuisLopez-sc1qc 11 ай бұрын

En ESPÑOL clases o jemeplos de DASH no hay casi nada todo en inglés... Dónde hay videos en Español

@casimirdesarmeaux3901 Жыл бұрын

Not all heroes wear capes

@ArjanCodes Жыл бұрын

Thanks so much

@vivekdabholkar5965 Жыл бұрын

Unable to install dash_bootstrap_components

@ChrisC-fk4lq Жыл бұрын

@24:30 to check if a dataframe is empty, you can use "filtered_data.empty == True" instead of "filtered_data.shape[0] == 0"

@rajeevmenon1975 Жыл бұрын

The video was very interesting, but it could have been made a bit more easy to understand. Maybe it assumed awareness of Html, css knowledge.

@JohnZakaria Жыл бұрын

I hate dash, the amount of http requests being sent is unfathomable. For every drop-down menu you click, dash will send a networks request to figure out what to do with it. Since dash is using flask, you are also using http1 by default which limits the amount of concurrent requests you can make. Another issue I have is the lack of separation between update action invokation. You can't include the same component in 2 different methods, even if the signature is different. Thus you start hacking your way to make the function do 2 things.

@ChrisC-fk4lq Жыл бұрын

what are some good alternatives to dash ?

@JohnZakaria Жыл бұрын

@@ChrisC-fk4lq We switched to Fastapi + React and never looked back. The added complexity was worth it.

@throblet Жыл бұрын

I too HATE the use of “magic” functionality to make things work. To me it smacks of poor design philosophy but it gets the job done I suppose. Ho hum…

@manarma7536 Жыл бұрын

great tutorial, but if i can make some suggestion, red lines are really distracting

@UNgineering Жыл бұрын

HTML in Python feels so wrong! excellent tutorial though!

@ArjanCodes Жыл бұрын

I know, it’s jarring isn’t it!

@uGetkilled Жыл бұрын

@@ArjanCodes next up, PyScript? :D

@SP-bk7ns Жыл бұрын

이런 강의를 공짜로 듣기에 너무 미안했다...

@ArjanCodes Жыл бұрын

Thank you - glad you like it!

@smatsri Жыл бұрын

I don't think python is a good choice for creating UI

@RobinZuFALL Жыл бұрын

Great Video! I prefer to use: filtered_data = MEDAL_DATA[MEDAL_DATA['nation'].isin(nations)]

@Zonkin Жыл бұрын

Instead of query, i would have used the isin() method in Pandas. MEDAL_DATA[MEDAL_DATA[‘nation’].isin(nations)] There’s a filter method as well, but I feel the .loc patterns are more powerful.

@LuisLopez-sc1qc 6 ай бұрын

enseñen como publicarlo para compartir a otra personas

@Zoltag00 Жыл бұрын

filtered_data.shape[0] == 0 is not particularly user friendly. I'd suggest filtered_data.empty as a check that makes more sense. To fix your nations IDE problem, I'd recommend using MEDAL_DATA[MEDAL_DATA.nation.isin(nations)], though I actually think your query syntax is a nicer syntax for maintainability