Returns a new object with all original columns in addition to new ones. Existing columns that are re-assigned will be overwritten. Show
The column names are keywords. If the values are callable, they are computed on the DataFrame and assigned to the new columns. The callable must not change input DataFrame (though pandas doesn’t check it). If the values are not callable, (e.g. a Series, scalar, or array), they are simply assigned. ReturnsDataFrameA new DataFrame with the new columns in addition to all the existing columns. Notes Assigning multiple columns within the same Examples >>> df = pd.DataFrame({'temp_c': [17.0, 25.0]}, ... index=['Portland', 'Berkeley']) >>> df temp_c Portland 17.0 Berkeley 25.0 Where the value is a callable, evaluated on df: >>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32) temp_c temp_f Portland 17.0 62.6 Berkeley 25.0 77.0 Alternatively, the same behavior can be achieved by directly referencing an existing Series or sequence: >>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32) temp_c temp_f Portland 17.0 62.6 Berkeley 25.0 77.0 You can create multiple columns within the same assign where one of the columns depends on another one defined within the same assign: Create new DataFrame by divide both columns and rename columns by Ever thought you could build a real-time dashboard in Python without writing a single line of HTML, CSS, or Javascript? Yes, you can! In this post, you’ll learn:
Can’t wait and want to jump right in? Here's the code repo and the video tutorial. What’s a real-time live dashboard?A real-time live dashboard is a web app used to display Key Performance Indicators (KPIs). If you want to build a dashboard to monitor the stock market, IoT Sensor Data, AI Model Training, or anything else with streaming data, then this tutorial is for you. 1. How to import the required libraries and read input dataHere are the libraries that you’ll need for this dashboard:
Go ahead and import all the required libraries:
You can read your input data in a CSV by using 3. But remember, this data source could be streaming from an API, a JSON or an XML object, or even a CSV that gets updated at regular intervals.Next, add the 3 call within a new function 5 so that it gets properly cached.What's caching? It's simple. Adding the decorator 6 will make the function 5 run once. Then every time you rerun your app, the data will stay memoized! This way you can avoid downloading the dataset again and again. Read more about caching in Streamlit docs.
2. How to do a basic dashboard setupNow let’s set up a basic dashboard. Use 8 with parameters serving the following purpose:
3. How to design a user interfaceA typical dashboard contains the following basic UI design components:
Let’s drill into them in detail. Page title The title is rendered as the <h1> tag. To display the title, use 2. It’ll take the string “Real-Time / Live Data Science Dashboard” and display it in the Page Title.
Top-level filter First, create the filter by using 3. It’ll display a dropdown with a list of options. To generate it, take the unique elements of the 4 column from the dataframe df. The selected item is saved in an object named 5:
Now that your filter UI is ready, use 5 to filter your dataframe df.
KPIs/summary cards Before you can design your KPIs, divide your layout into a 3 column layout by using 7. The three columns are kpi1, kpi2, and kpi3. 8 helps you create a KPI card. Use it to fill one KPI in each of those columns. 8’s label helps you display the KPI title. The value **is the argument that helps you show the actual metric (value) and add-ons like delta to compare the KPI value with the KPI goal.
Interactive charts Split your layout into 2 columns and fill them with charts. Unlike the metric above, use the 0 clause to fill the interactive charts in the respective columns:
Data table Use 1 to display the data frame. Remember, your data frame gets filtered based on the filter option selected at the top:
4. How to refresh the dashboard for real-time or live data feedSince you don’t have a real-time or live data feed yet, you’re going to simulate your existing data frame (unless you already have a live data feed or real-time data flowing in). To simulate it, use a 2 loop from 0 to 200 seconds (as an option, on every iteration you’ll have a second 3/pause):
Inside the loop, use NumPy's 4 to generate a random number between 1 to 5. Use it as a multiplier to randomize the values of age and balance columns that you’ve used for your metrics and charts.5. How to auto-update componentsNow you know how to do a Streamlit web app! To display the live data feed with auto-updating KPIs/Metrics/Charts, put all these components inside a single-element container using 5. Call it 6: 0Put your components inside the 6 by using a 0 clause. This way you’ll replace them in every iteration of the data update. The code below contains the 9 along with the UI components you created above: 1And...here is the full code! 2To run this dashboard on your local computer:
Wrapping upCongratulations! You have learned how to build your own real-time live dashboard with Streamlit. I hope you had fun along the way. If you have any questions, please leave them below in the comments or reach out to me at [email protected] or on Linkedin. Apa yang dimaksud dengan data frame?Dataframe merupakan tabel atau data tabular dengan array dua dimensi yaitu baris dan kolom. Struktur data ini merupakan cara paling standar untuk menyimpan data. Setiap kolom pada dataframe merupakan objek dari Series, dan baris terdiri dari elemen yang ada pada Series.
Apa itu Pandas pada python?Nah dalam hal ini Library Pandas berarti sebuah library open source yang ada pada bahasa pemrograman Python yang sering digunakan untuk memproses data, mulai pembersihan data, manipulasi data, hingga melakukan analisis data.
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