Date formatting with mdates in Matplotlib - Mini Project: Build & Apply

Date formatting with mdates

📖 Scenario: You are analyzing daily sales data for a small shop. You want to plot the sales over a week and show the dates nicely on the x-axis.

🎯 Goal: Create a line plot of sales over dates and format the x-axis dates using mdates for clear date labels.

📋 What You'll Learn

Create a list of dates for one week using datetime.date

Create a list of sales numbers matching the dates

Use matplotlib to plot sales vs dates

Use mdates to format the x-axis dates as 'Day-Month'

Display the plot with formatted date labels

💡 Why This Matters

🌍 Real World

Date formatting is important when visualizing time series data like sales, weather, or stock prices to make charts easy to read.

💼 Career

Data scientists and analysts often use date formatting to create clear and professional time-based visualizations for reports and presentations.

1

Create the dates and sales data

Create a list called dates with these exact datetime.date values: 2024-06-01, 2024-06-02, 2024-06-03, 2024-06-04, 2024-06-05, 2024-06-06, 2024-06-07. Also create a list called sales with these exact values: 150, 200, 170, 220, 180, 210, 190.

Matplotlib

import datetime
# Create the list 'dates' with the exact dates
# Create the list 'sales' with the exact sales numbers
# Your code here

Need a hint?

Use datetime.date(year, month, day) to create each date.

2

Set up the date formatter

Import matplotlib.pyplot as plt and matplotlib.dates as mdates. Create a variable called date_format that uses mdates.DateFormatter to format dates as '%d-%b' (day and abbreviated month).

Matplotlib

import datetime

import matplotlib.pyplot as plt
import matplotlib.dates as mdates

# Create the date formatter with format '%d-%b'
# Your code here

Need a hint?

Use mdates.DateFormatter('%d-%b') to create the formatter.

3

Plot the sales data with formatted dates

Use plt.plot to plot dates on the x-axis and sales on the y-axis. Then get the current axes with ax = plt.gca(). Use ax.xaxis.set_major_formatter(date_format) to apply the date formatter to the x-axis.

Matplotlib

import datetime

import matplotlib.pyplot as plt
import matplotlib.dates as mdates

# Plot dates vs sales
# Get current axes as 'ax'
# Set x-axis major formatter to 'date_format'
# Your code here

Need a hint?

Use plt.plot(dates, sales) to plot, then ax = plt.gca() and ax.xaxis.set_major_formatter(date_format).

4

Display the plot

Write plt.show() to display the plot with the formatted date labels on the x-axis.

Matplotlib

import datetime

import matplotlib.pyplot as plt
import matplotlib.dates as mdates

# Show the plot
# Your code here

Need a hint?

Use plt.show() to display the plot window.