Data Visualization using Matplotlib and Seaborn · Lesson 1 of 1
Data Visualization using Matplotlib and Seaborn
Choose charts that match analytical questions and build readable Matplotlib and Seaborn visualizations.
Lesson
1. Introduction
A chart is a visual argument about data. Its job is to make a comparison, trend, distribution, or relationship easier to see without hiding scale, uncertainty, or context.
2. Core concepts
Use position and length for precise comparisons, lines for ordered trends, histograms for distributions, and scatter plots for relationships between numeric values. Seaborn supplies statistical chart defaults built on Matplotlib; both still require thoughtful labels and data choices.
3. Topics covered in this module
- Figure, axes, labels, legends, scales, and layout
- Bars, lines, pies, stacked areas, histograms, scatter plots, and subplots
- Seaborn distributions, categorical plots, themes, and statistical estimates
- Chart selection, misleading scales, uncertainty, accessibility, and annotation
4. Syntax and how to read it
import matplotlib.pyplot as plt
plt.bar(regions, revenue)
plt.xlabel('Region')
plt.ylabel('Revenue (USD)')
plt.title('Revenue by region')
plt.tight_layout()Labels and units explain the encoding. Call plt.show() in a script or rely on the notebook display integration to render the figure.
5. Practical workflow
Write the question as a comparison, select a chart that matches the variable types, and show units and sample context. Inspect outliers and missing values before choosing axis limits or smoothing.
6. Common mistakes
- Using a truncated bar-chart axis that exaggerates small differences.
- Adding a pie chart with many categories or a chart whose color has no accessible label.
7. Best practices
- Label axes with units and disclose aggregation and date range.
- Use color palettes with sufficient contrast and do not rely on color alone.
8. Practice task
You want to show the distribution of delivery times for three regions. Choose a chart and name one useful axis.
9. One possible solution
A box plot or violin plot can compare distributions; use Region on the category axis and Delivery time (days) on the value axis.10. Summary
Choose charts that match analytical questions and build readable Matplotlib and Seaborn visualizations. Label axes with units and disclose aggregation and date range. Use color palettes with sufficient contrast and do not rely on color alone.
11. What comes next
The next module, Data Collection, Requests, and Web Scraping, builds on this foundation and applies it to a new part of the analytics workflow.
Visual guide
A reliable Data Visualization using Matplotlib and Seaborn workflow
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Step 01
Frame
Define the question, input scope, and intended output.
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Step 02
Work
Apply the method and validate assumptions as you go.
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Step 03
Check
Compare results with known cases and communicate limitations.
Code examples
import matplotlib.pyplot as plt
plt.plot(months, signups, marker='o')
plt.xlabel('Month')
plt.ylabel('Sign-ups')
plt.grid(True, alpha=0.3)
A line chart showing sign-ups across ordered months.
import seaborn as sns
sns.boxplot(data=frame, x='region', y='delivery_days')
A distribution comparison of delivery time by region.
Key points
- Choose charts that match analytical questions and build readable Matplotlib and Seaborn visualizations.
- Label axes with units and disclose aggregation and date range.
- Use color palettes with sufficient contrast and do not rely on color alone.
Check your understanding
Practice
Your learning progress