Lesson 3 of 3

Module 3 · pandas Quick Start

Group, Join and Chart

Summarise data with groupby, join tables with merge, and turn the answers into charts you can share.

About 25 minutes

Open in ColabEvery example as a notebook you can run, edit and save to your Google Drive.

Summarise with groupby

groupby is the pandas version of a pivot table. Total revenue by year:

Six rows split into North and South groups, each summed, giving North 500 and South 450 — groupby: split into groups, calculate for each, combine the results.TapClick the image to see it full size.

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Revenue by month, then the best and worst months:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Join tables with merge

The orders table only has product_id and customer_id. The names, categories and regions live in two other tables. Load them and merge:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

merge matches rows where the key column has the same value, like a lookup in Excel.

An orders table and a products table are matched on product_id, so each order gains the product name — merge matches rows on a key column, like a lookup in Excel.TapClick the image to see it full size.

Answer business questions

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Category	Revenue
Household	₦244,769,040
Personal care	₦235,483,370
Beverages	₦224,612,360
Snacks	₦125,676,475

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Lagos brings in ₦411,162,300, about half of all revenue, followed by South West and North West.

Make charts

pandas can draw charts directly:

Two charts drawn with illustrative numbers: a bar chart comparing four product groups and a line chart of monthly revenue rising to a peak in May, with the pandas plot code — Bars compare categories; lines show change over time.TapClick the image to see it full size.

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Use kind="barh" for comparing categories and a line (the default) for trends over time.

Add text cells to explain what you found in plain words, not just code. Then save the notebook to GitHub (File → Save a copy in GitHub) or share the Colab link. That's a portfolio project.

Try it

Use the merged sales table.

Practice

Which channel brings in the most revenue?

Practice

Which product (product_name) brings in the most revenue?

Task

12 min

Make a bar chart of revenue by region and a line chart of monthly revenue. Then write three sentences for a manager summarising what they show, with at least two numbers.

Your work is checked for

Three sentences
At least two numbers
Mentions a region
Says something about change over time (month, December, grew, fell, peak…)
Written for a manager, not code (no brackets or underscores)

Then save the notebook to GitHub (File → Save a copy in GitHub) or share the Colab link with a text cell at the top explaining what it does.

Earn your badge

Take the module check

Questions on this module. Pass and you earn the Python Data Insights badge, free.

Create a free account to earn the badge

Lesson 3 of 3

Module 3 · pandas Quick Start

Group, Join and Chart

Summarise data with groupby, join tables with merge, and turn the answers into charts you can share.

About 25 minutes

Open in ColabEvery example as a notebook you can run, edit and save to your Google Drive.

Summarise with groupby

groupby is the pandas version of a pivot table. Total revenue by year:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Revenue by month, then the best and worst months:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Join tables with merge

The orders table only has product_id and customer_id. The names, categories and regions live in two other tables. Load them and merge:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

merge matches rows where the key column has the same value, like a lookup in Excel.

Answer business questions

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Category	Revenue
Household	₦244,769,040
Personal care	₦235,483,370
Beverages	₦224,612,360
Snacks	₦125,676,475

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Lagos brings in ₦411,162,300, about half of all revenue, followed by South West and North West.

Make charts

pandas can draw charts directly:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Use kind="barh" for comparing categories and a line (the default) for trends over time.

Add text cells to explain what you found in plain words, not just code. Then save the notebook to GitHub (File → Save a copy in GitHub) or share the Colab link. That's a portfolio project.

Try it

Use the merged sales table.

Practice

Which channel brings in the most revenue?

Practice

Which product (product_name) brings in the most revenue?

Task

12 min

Make a bar chart of revenue by region and a line chart of monthly revenue. Then write three sentences for a manager summarising what they show, with at least two numbers.

Your work is checked for

Three sentences
At least two numbers
Mentions a region
Says something about change over time (month, December, grew, fell, peak…)
Written for a manager, not code (no brackets or underscores)

Then save the notebook to GitHub (File → Save a copy in GitHub) or share the Colab link with a text cell at the top explaining what it does.

Earn your badge

Take the module check

Questions on this module. Pass and you earn the Python Data Insights badge, free.

Create a free account to earn the badge

Summarise with groupby

Join tables with merge

Answer business questions

Make charts

Share your analysis

Try it

Take the module check

Summarise with groupby

Join tables with merge

Answer business questions

Make charts

Share your analysis

Try it

Take the module check