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Fast Dash

Open source, Python-based tool to build prototypes lightning fast ⚡

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Fast Dash is a Python module that makes the development of web applications fast and easy. It can build web interfaces for Machine Learning models or to showcase any proof of concept without the hassle of developing UI from scratch.



With Fast Dash's decorator @fastdash, it's a breeze to deploy any Python function as a web app. Here's how to use it to write your first Fast Dash app:

from fast_dash import fastdash

def text_to_text_function(input_text):
    return input_text

# * Running on (Press CTRL+C to quit)

And just like that, we have a completely functional interactive app!

Output: Simple example

Fast Dash can read all the function details, like its name, input and output types, docstring, and uses this information to infer which components to use.

For example, here's how to deploy an app that takes a string and an integer as inputs and returns some text.

from fast_dash import fastdash

def display_selected_text_and_number(text: str, number: int) -> str:
    "Simply display the selected text and number"

    processed_text = f'Selected text is {text} and the number is {number}.'

    return processed_text

# * Running on (Press CTRL+C to quit)

Output: Simple example with multiple inputs

And with just a few more lines, we can add a title icon, subheader and other social branding details.

Output components can be arranged using a mosaic layout (ASCII art), inspired from Matplotlib's subplot_mosaic feature.

from fast_dash import fastdash, UploadImage, Graph
import matplotlib.pyplot as plt

mosaic = """

@fastdash(mosaic=mosaic, theme="BOOTSTRAP")
def multiple_output_components(start_date:, # Adds a date component
                            upload_image: UploadImage, # Adds an upload component
                            fips: str = [List of FIPs]) # Adds a single select dropdown
                            -> (Graph, plt.Figure, plt.Figure): 
                            # Output components are a Plotly graph, and two figure components

    "Fast Dash allows using mosaic arrays to arrange output components"

    choropleth_map = ...
    histogram = ...
    radar_chart = ...

    return chloropleth_map, histogram, radar_chart

# * Running on (Press CTRL+C to quit)
Simple example with multiple inputs

In just a few lines of code, you can also add a chat component.

Simple chat

You can use your favorite Python libraries. Here's an example of an advanced geospatial application built using geemap and Google Earth Engine.

Water spectral indices


Read different ways to build Fast Dash apps and additional details by navigating to the project documentation.

Key features

Duild and deploy a web app by adding a decorator only. - Components are inferred from function type hints. Allows using Dash components as type hints. - Use multiple input and output components simultaneously. - Build fast, share and iterate.


Fast Dash is built using Plotly Dash and it's completely open-source.