Plotly Python Tutorial – Complete Guide

Delving into the world of data can be intimidating for beginners, yet with the right tools, it becomes an exciting exploration of patterns and insights. Python, a leading language in data analysis and visualization, offers numerous libraries to simplify this process. Among these, Plotly stands out for its versatility and user-friendliness. This tutorial aims to provide a comprehensive understanding of Plotly in Python, making data visualization enjoyable and accessible to all.

What is Plotly?

Plotly is a Python library primarily used for data visualization. It supports over 40 unique chart types encompassing a wide range of statistical, financial, geographic, scientific, and 3-dimensional graphics.

Plotly is uniquely interactive – it enables users to zoom, pan, hover over, and interact with the plots in various ways that static charts do not support. It also allows sharing and exporting the generated plots easily in several formats.

With data-driven decision making becoming crucial across sectors, having skills in data visualization provides a competitive edge. Learning Plotly gives you a powerful tool to represent complex data structures in an intuitive and engaging way.

It’s user-friendly approach and vast community contribute to making Plotly an ideal starting point for beginners, yet its wide range of capabilities ensure it continues to be a valuable tool as you delve deeper into data analysis.

CTA Small Image
FREE COURSES AT ZENVA
LEARN GAME DEVELOPMENT, PYTHON AND MORE
ACCESS FOR FREE
AVAILABLE FOR A LIMITED TIME ONLY

Getting Started with Plotly

The first step is to install Plotly’s Python library. That’s fairly simple and can be done using pip. Just use the following command:

pip install plotly

Importing Plotly

Upon successfully installing Plotly, the next step is to import it into your Python script. We’ll use the “graph_objs” module, which includes all the tools required to create plots:

import plotly.graph_objs as go

Drawing a Line Chart

To begin with something simple, let’s create a line chart. We will use the “go.Figure” function to initialize our figure object, and then the “add_trace” method to add our line chart to it:

fig = go.Figure()
fig.add_trace(go.Scatter(y=[2, 3, 1, 4]))
fig.show()

Creating a Bar Chart

Now, let’s create a basic bar chart. Note that the X and Y values are passed as lists to their respective parameters:

fig = go.Figure(data=go.Bar(y=[2, 3, 1, 4]))
fig.show()

Creating a Heatmap

Heatmaps are a powerful tool for data visualization. They are primarily used to represent complex data in an easily interpretable graphical format. Here’s how you can make a heatmap using Plotly:

fig = go.Figure(data=go.Heatmap(z=[[1, 20, 30],[20, 1, 60],[30, 60, 1]]))
fig.show()

In the above code, ‘z’ represents the color scale values. It is a 2D list containing the color values for the heatmap.

Moving on to 3D plots

Plotly’s flexibility extends to 3-Dimensional plots as well, like this 3D scatter plot:

fig = go.Figure(data=[go.Scatter3d(x=[1, 2, 3], y=[4, 5, 6], z=[7, 8, 9], mode='markers')])
fig.show()

With the ‘markers’ mode, the points are represented as distinct markers in the graph.

Box Plots

Box plots, another powerful visualization tool, help in understanding the distribution of data. Generating a box-plot using Plotly is as simple as:

fig = go.Figure(data=go.Box(y=[0, 1, 2, 3, 5, 9, 10, 7, 6, 4, 8]))
fig.show()

Area Plots

Area plots, a variant of the line charts, represent the quantity through the area between the axis and the line. Here’s how to create one:

fig = go.Figure(data=go.Scatter(x=[1, 2, 3, 4], y=[10, 15, 13, 17], fill='tozeroy'))
fig.show()

Histograms

Histograms are specifically used to represent the frequency distribution of data sets. To represent a dataset using a histogram, use:

fig = go.Figure(data=[go.Histogram(x=[1, 2, 2, 3, 3, 3, 4, 4, 4, 4])])
fig.show()

Pie Charts

Who doesn’t love a good pie chart! These are used mainly to represent categorical data:

fig = go.Figure(data=[go.Pie(labels=['A', 'B', 'C'], values=[10, 15, 7])])
fig.show()

Violin Plots

Violin plots are similar to box plots but also include a kernel density estimation of the data at different values. Here’s an example:

fig = go.Figure(data=go.Violin(y=[1, 2, 3, 4, 4, 4, 8, 10]))
fig.show()

Scatter Plots with a trendline

Trendlines are an important tool in understanding the patterns in scatter plot data. Here’s how to include a trendline in your scatter plot:

import plotly.express as px
df = px.data.tips() # builtin Plotly dataset
fig = px.scatter(df, x="total_bill", y="tip", trendline="ols")
fig.show()

In the above code, ‘ols’ stands for ‘Ordinary Least Squares’, which is a type of linear least squares method for estimating the trendline.

Where To Go Next?

Now that you’ve made your first steps into data visualization with Plotly, the world of Python programming is open to explore even further. Your journey doesn’t stop here, there’s lots more to learn and create!

A fantastic place to continue your journey with Python is with our Python Mini-Degree. This robust collection of courses teaches Python programming in depth through various engaging topics such as coding basics, algorithms, object-oriented programming, game development, and app development.

The best part? You’ll be learning through hands-on projects! This means you get to build games, apps, and other real-world projects as part of your learning journey. This practical, project-based approach is not only more engaging, but it allows you to apply and retain the concepts as you learn them.

No matter whether you’re a beginner wanting to dive into coding, or an experienced programmer seeking to expand your skill set, our Python Mini-Degree has courses that are just right for you.

For those who’d like to explore an even broader range of Python content, do not hesitate to check out our collection of Python courses.

Conclusion

Data is the driving force behind most of the decisions we make today, and having the ability to visualize this data in a meaningful way puts you at the driving seat of progress. Learning Plotly is a valuable skill that provides you with a competitive edge in today’s data-driven world, and we’ve just scratched the surface.

If you enjoyed this introduction to Plotly, feel inspired, and want to dive deeper into the fascinating world of Python and data visualization, consider joining our Python Mini-Degree. You’ll gain comprehensive, practical knowledge that will propel your programming career forward. Reinforce your skills, spur creativity, and bring your innovative ideas to life with Zenva. We look forward to being part of your exciting learning journey!

Did you come across any errors in this tutorial? Please let us know by completing this form and we’ll look into it!

FREE COURSES
Python Blog Image

FINAL DAYS: Unlock coding courses in Unity, Godot, Unreal, Python and more.