05 Build UI interface in JupyterLab

Build UI interfaces in JupyterLab

Building UI interfaces in JupyterLab typically uses the ipywidgets library, which provides a simple yet powerful way to create interactive user interfaces. Here are the detailed steps:

Import the required libraries

The ipywidgets library has been installed in our product. If you can't find the library when you run the block, you can install the library you need in the UI by pip install ipywidgets.

Select the following code block and press Ctrl + Enter to run the code.

import ipywidgets as widgets 
from IPython.display import display

Create UI Components

We can use various components from the ipywidgets library to build our UI interface, such as text boxes, buttons, output boxes, etc. For example:

# Create a text box 
text = widgets. Text(description='Please enter a name:')

# Create a button 
button = widgets. Button(description="Say hello")

# Create an output box 
output = widgets. Output()

Define Event Handler

We need to define a handler that handles user interaction events. In this example, we'll define a function to handle the click event of the button and display a greeting in the output box.

# Define a function greet_user that takes a sender argument that represents the object that triggers the event, such as a button 
def greet_user(sender): 
   # Use the with statement and the output object to capture the output of the print function so that it appears in the expected output area 
   # output is the output object that has been defined 
   with output: 
       # Use the print function to output a greeting where the format method is used to insert the current value of the text control into the string 
       # "{}" is a placeholder that the format function replaces with the value of text.value 
       print("Hello, {}".format(text.value))

# Use the on_click method to associate the button's click event with the greet_user function 
# When the user clicks the button, the greet_user function is called
button.on_click(greet_user)

Show UI interface

Finally, we put all the UI components in a layout and display them through the display function.

# Put all the components in a vertical layout 
ui = widgets. VBox([text, button, output])

# Display UI 
display(ui)

With these steps, we can build a simple UI in JupyterLab. The user can enter the content in the text box, and after clicking the button, the program will display the corresponding greeting in the output box according to the input content.