Wildfire Data Visualization with Preswald

Amrutha Gujjar•March 18, 2025•3 min read

We're thrilled to feature Oscar Herrera in this edition of the Preswald Community Showcase! 🎉 Oscar has built an impressive Preswald app that analyzes and visualizes wildfire occurrences and trends using interactive charts and tables.

🌟 Project Overview

Project Name: Wildfire Data Explorer
Built by: Oscar Herrera
Dataset: Wildfire incident dataset

Check out the project on GitHub

📊 Description

Oscar's project provides an interactive dashboard for exploring wildfire trends. The app allows users to:

Filter wildfire incidents based on location, date, and severity.
Visualize trends using Plotly charts to track wildfire occurrences over time.
Sort and search wildfire data dynamically in an interactive table.
Gain insights into wildfire patterns and areas most affected.

With Preswald, Oscar has created a seamless user experience, where users can dynamically change inputs and get instant updates without writing frontend code.

🚀 Code Snippets

Here’s a sneak peek at how Oscar's project is structured:

Loading the Data

from preswald import connect, get_df, text

connect()  # Establish connection to data

# Load wildfire dataset
wildfire_df = get_df("wildfire_data")

Creating an Interactive Time-Series Chart

from preswald import plotly
import plotly.express as px

fig = px.line(wildfire_df, x='date', y='number_of_fires', color='location',
             title='Wildfire Occurrences Over Time')
plotly(fig)

Displaying Wildfire Data in a Table

from preswald import table

table(wildfire_df[['date', 'location', 'severity', 'number_of_fires']])

With just a few lines of Python, Oscar has built a fully interactive data app powered by Preswald! 🚀

What is Preswald?

Preswald is an open-source framework for building data apps, dashboards, and internal tools with just Python. It provides pre-built UI components like tables, charts, and forms, so you don't have to write frontend code. Users can interact with your app, changing inputs, running queries, and updating visualizations, without you needing to manage the UI manually.

Preswald tracks state and dependencies, making computations efficient by updating only when necessary. It uses a workflow DAG to manage execution order, ensuring performance and predictability. Preswald allows you to turn Python scripts into shareable, production-ready applications easily.

Key Features

Add UI components to Python scripts: user-interactive buttons, text inputs, tables, and charts.
Stateful execution with automatic state tracking and updates.
Structured computation using a DAG-based execution model.
Deploy with a single command.
Query and display live data from various sources.
Build interactive reports and dashboards.
Easy local or cloud hosting.
Shareable via a simple link.

🚀 Getting Started

Installation

First, install Preswald via pip: https://pypi.org/project/preswald/

pip install preswald

👩‍💻 Quick Start

1. Initialize a New Project

To start using Preswald, initialize a new project:

preswald init my_project
cd my_project

This creates a folder my_project with essential files:

hello.py: Your first Preswald app.
preswald.toml: Settings for your app.
secrets.toml: Secure sensitive information.
.gitignore: Keep secrets.toml safe from version control.

2. Write Your First App

Open hello.py and write:

from preswald import text, plotly, connect, get_df, table
import pandas as pd
import plotly.express as px

text("# Welcome to Preswald!")
text("This is your first app. 🎉")

# Load CSV data
connect() # loads default sample CSV
df = get_df('sample_csv')

# Create a scatter plot
fig = px.scatter(df, x='quantity', y='value', text='item',
                 title='Quantity vs. Value')
fig.update_traces(textposition='top center')
fig.update_layout(template='plotly_white')

# Show plot and data
table(df)

3. Run Your App

Launch the app with:

preswald run

4. Deploy Your App to the Cloud

Deploy your app using:

preswald deploy --target structured

Your app will be built and accessible online.

Huge Thanks to Oscar Herrera!

A big thank you to Oscar Herrera for sharing their work and inspiring the Preswald community! Want to see more of their work? Check them out on Linkedin or GitHub.

Want to Contribute?

Got a cool idea for a Preswald app? We'd love to see it! Get started here: https://github.com/StructuredLabs/preswald and get featured in our next Community Showcase. Happy building! 🚀

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