APIs

Panel can be used to make a first pass at an app or dashboard in minutes, while also allowing you to fully customize the app's behavior and appearance or flexibly integrate GUI support into long-term, large-scale software projects. To make all these different ways of using Panel possible, four different APIs are available:

  • Interact functions: Auto-generates a full UI (including widgets) given a function
  • Reactive functions: Linking functions or methods to widgets using the pn.depends decorator, declaring that the function should be re-run when those widget values change
  • Parameterized class: Declare parameters and their ranges in Parameterized classes, then get GUIs (and value checking!) for free
  • Callbacks: Generate a UI by manually declaring callbacks that update panels or panes

Each of these APIs has its own benefits and drawbacks, so this section will go through each one in turn, while working through an example app and pointing out the benefits and drawback along the way. For a quick overview you can also review the API gallery examples, e.g. the stocks_hvplot app.

To start with let us define some imports, load the autompg dataset, and define a plotting function we will be reusing throughout this user guide.

In [1]:
import hvplot.pandas
from bokeh.sampledata.autompg import autompg

def autompg_plot(x='mpg', y='hp', color='#058805'):
    return autompg.hvplot.scatter(x, y, c=color, padding=0.1)

columns = list(autompg.columns[:-2])