Plotly and the Plotly Figure

Introducción a la visualización de datos con Plotly en Python

Alex Scriven

Data Scientist

What is Plotly?

 

  • A JavaScript graphing library
    • Don't worry - no need to know JavaScript!
  • Plotly has a Python wrapper

 

Plotly logo

Introducción a la visualización de datos con Plotly en Python

Why Plotly?

 

Plotly has a number of unique advantages:

  • Fast and easy to use
  • Low code/low effort options using plotly.express
  • (If desired) Extremely customizable
  • Built-in interactivity
Introducción a la visualización de datos con Plotly en Python

Creating Plotly Figures

 

Plotly graphs can be created:

  1. With plotly.express for quick plots (px)
  2. With plotly.graph_objects (go) for more customization

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📈 We will spend most of our time on px

Introducción a la visualización de datos con Plotly en Python

The importance of documentation

Save the links to key documentation!

  1. Interactive documentation

  2. Detailed reference page for specific plots

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For Scatter plots:

Introducción a la visualización de datos con Plotly en Python

Creating our Figure

  A basic plotly figure:

import plotly.express as px

days = ["Monday", "Tuesday", "Wednesday", "Thursday", 
        "Friday", "Saturday", "Sunday"]       
temperatures = [28, 27, 25, 31, 32, 35, 36]

fig = px.bar(
    x=days, 
    y=temperatures,
    title="Temperatures of the week")

fig.show()
Introducción a la visualización de datos con Plotly en Python

Our Figure revealed

Bar chart of weekly temperatures

Introducción a la visualización de datos con Plotly en Python

The Plotly Figure

 

Plotly Figure components:

  • layout: Dictionary controlling style of the figure
    • One layout per figure
  • data: List of dictionaries setting graph type and data itself
    • Data + type = a trace. There are over 40 types!
    • Can have multiple traces per graph
  • frames: For animated plots (beyond this course)
Introducción a la visualización de datos con Plotly en Python

Inside a Plotly Figure

 

print(fig)

Figure({'data': [{'type': 'bar',
              'x': array(['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday'
              , 'Saturday','Sunday'], dtype=object),
              'y': {'bdata': 'HBsZHyAjJA==....'}],
    'layout': {'title': {'text': 'Temperatures of the week'}}})
Introducción a la visualización de datos con Plotly en Python

Plotly's instant interactivity

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  • Hover over data points
  • Extra interactive buttons

Hover options

Introducción a la visualización de datos con Plotly en Python

Let's practice!

Introducción a la visualización de datos con Plotly en Python

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