Q: When should I use a debugger instead of print statements?

Use pdb or Node.js Inspector when you need to inspect variable state step by step, examine complex call stacks, or pause execution conditionally. Print or log statements work better for quick traces and production diagnostics.

Question 1

How do I debug a Python error systematically?

Accepted Answer

Start by collecting the complete error message, stack trace, and reproduction steps. Then classify the error type, use binary search or logging to locate the source, form a hypothesis about the cause, and verify it before applying a fix.

Question 2

How to debug Bash scripts that fail silently?

Accepted Answer

Run the script with bash -x to trace each command, and add set -euo pipefail at the top to exit on errors, catch undefined variables, and fail on broken pipes. Use trap handlers to log the failing line number.

Question 3

What are common Python error patterns to check first?

Accepted Answer

Frequent culprits include mutable default arguments, modifying a list while iterating, closure variable binding in loops, using is for value comparison, and forgetting to call super().__init__(). Checking these patterns first often resolves bugs quickly.

Question 4

Why does my shell script variable lose its value inside a loop?

Accepted Answer

Piping into a while loop creates a subshell, so variable changes do not persist outside it. Use input redirection or process substitution like done < file.txt instead of cat file.txt | while read to keep the variable in the current shell.

Question 5

When should I use a debugger instead of print statements?

Accepted Answer

Use pdb or Node.js Inspector when you need to inspect variable state step by step, examine complex call stacks, or pause execution conditionally. Print or log statements work better for quick traces and production diagnostics.

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