Always label your charts
Without labels, your chart is incomplete. McKinney's rule of thumb: set_xlabel names
the x-axis, set_title names the whole subplot, and both can be set together with one
call to ax.set(title=..., xlabel=..., ylabel=...) — handy once you're labelling many
subplots at once.
flowchart LR
A["Raw plot"] --> B["ax.set_xlabel('Day')"]
B --> C["ax.set_ylabel('Orders')"]
C --> D["ax.set_title('what changed, not just the chart type')"]
D --> E["Reader understands the chart without extra context"]
import matplotlib.pyplot as plt
x = [1, 2, 3, 4]
y = [100, 120, 90, 150]
plt.figure(figsize=(7, 4))
plt.plot(x, y, marker="o")
plt.title("Daily orders")
plt.xlabel("Day")
plt.ylabel("Orders")
plt.tight_layout()
plt.show()Include units
Examples:
- Revenue (₹)
- Duration (seconds)
- Conversion rate (%)
Tip
A good title explains the question, not just the chart type.
Bad: "Line chart"
Better: "Daily orders increased after campaign launch"
Check your understanding
Which single call sets the title and both axis labels on an Axes?
ax.set combines several setters, which is handy when labelling many subplots.
Show answer
A — ax.set(title=..., xlabel=..., ylabel=...) — ax.set combines several setters, which is handy when labelling many subplots.
Which pyplot calls label the x-axis and y-axis?
plt.xlabel("Day") and plt.ylabel("Orders") label the axes, while plt.title names the chart.
Show answer
A — plt.xlabel and plt.ylabel — plt.xlabel("Day") and plt.ylabel("Orders") label the axes, while plt.title names the chart.
Which title does the lesson prefer?
A good title explains the question or finding, not just the chart type.
Show answer
A — Daily orders increased after campaign launch — A good title explains the question or finding, not just the chart type.
Why include units in axis labels?
Units make a number interpretable. Without labels the chart is incomplete.
Show answer
A — So readers know what Revenue (rupees), Duration (seconds) or Rate (%) measure — Units make a number interpretable. Without labels the chart is incomplete.
Next
Continue to Legends and Colors to distinguish multiple series clearly.
🧪 Try It Yourself
Exercise 1 – Title and axis labels together
Tab indents. Press Escape, then Tab, to leave the editor. Control plus Enter runs the code; Control plus Shift plus Enter submits it.
Press Run to see what your code prints.Exercise 2 – Custom tick labels
Tab indents. Press Escape, then Tab, to leave the editor. Control plus Enter runs the code; Control plus Shift plus Enter submits it.
Press Run to see what your code prints.Exercise 3 – Rotate long labels
Tab indents. Press Escape, then Tab, to leave the editor. Control plus Enter runs the code; Control plus Shift plus Enter submits it.
Press Run to see what your code prints.