Running code executes instructions; debugging pauses execution so you can inspect what is happening; stopping ends the running process.
Understanding the Concept
Create a short script that calculates a price. Use Run for normal execution. Click in the gutter next to a line to add a breakpoint, then use Debug. When execution pauses at the breakpoint, look at the Variables pane and Step Over through the next line. Resume continues running, and Stop terminates a process when you no longer want it to run. Breakpoints do not alter the underlying source logic.
When and Why You Would Use This
Debuggers are particularly helpful when a program prints an unexpected result. Instead of inserting many temporary print calls, inspect intermediate values and the execution sequence.
Practical Example
unit_price = 8
item_count = 4
subtotal = unit_price * item_count
print("Subtotal:", subtotal)Understanding the Example
Set a breakpoint on the subtotal line. Before stepping over it, unit_price is 8 and item_count is 4. After stepping over, subtotal becomes 32. The Run window prints Subtotal: 32 when the print statement executes.
Example Output
Subtotal: 32Try It Yourself
Set a breakpoint before print, inspect subtotal, then resume execution. Try a different item_count.
Common Beginner Mistakes
- Using Stop instead of Resume while inspecting a breakpoint, then wondering why the output is incomplete.
- Expecting a breakpoint to modify a variable. It only pauses execution for inspection.
- Debugging without checking which run configuration and interpreter are active.
Key Takeaways
- Run executes normally; Debug allows pausing and stepping.
- Breakpoints reveal the values immediately before or after selected statements.
- Stop terminates the process; Resume continues it.