A set of methods for finding and diagnosing problems in Python programs. It recommends stepping through code or measuring execution and memory use with tools suited to the specific problem.

For debugging Python code, tracing execution, profiling program or line performance, investigating memory growth, and making difficult debug output easier to read.

It helps identify whether a program is crashing, slow, or using too much memory before changing the code. It also recommends capturing reproducible incorrect behavior in a regression test when appropriate.

py-debug — Skill for Claude Code and Codex by berekvolgyipeter

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add berekvolgyipeter/dotclaude --skill py-debug

Clone the repo

git clone --depth 1 https://github.com/berekvolgyipeter/dotclaude

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/berekvolgyipeter/dotclaude/py-debug/github.svg)](https://agentmods.dev/skills/berekvolgyipeter/dotclaude/py-debug)

Your own site

<a href="https://agentmods.dev/skills/berekvolgyipeter/dotclaude/py-debug"><img src="https://agentmods.dev/badge/skills/berekvolgyipeter/dotclaude/py-debug/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/berekvolgyipeter/dotclaude/py-debug"><img src="https://agentmods.dev/badge/skills/berekvolgyipeter/dotclaude/py-debug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,037 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00054	$0.01037
Opus 5.5	$0.00022	$0.00415
Sonnet 5.5	$0.00011	$0.00207
Haiku 4.5	$0.00005	$0.00104

Measured 1mo ago against content hash 561328b96cef, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

py-debug scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/setup.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/py-debug/SKILL.md · 128 lines

How it starts

The opening of the file, as written. The whole thing — 128 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Python Debugging

Not sure what's wrong? Start with ipdb — step through the code and observe. Once you can characterize the problem (slow, leaking memory, crashing), switch to the matching profiler.

Problem	Tool
Need to step through execution interactively	`ipdb`
Which function is slow? (whole-program overview)	`cProfile` (stdlib)
Identifying slow lines in a function	`line-profiler`
Profile a running process without code changes	`py-spy`
Investigating memory growth or leaks	`memory-profiler`
Hard to read debug output (nested dicts, long lists, tracebacks)	`rich`

Behavioral Rules

Lock the bug with a failing test once reproduced — before patching incorrect behavior, capture the faulty behavior as a regression test (through the public interface where one exists), so the fix is verified and the bug can't silently regress; skip this for pure performance or memory investigations, where a test through the public interface is rarely the right artifact
Suggest only one tool per problem — don't list all options and ask the user to choose
Explain the fit in one sentence before showing usage — e.g. "Since you want line-by-line timing, line-profiler is the right tool here."
Prefer ipdb as the default for general debugging; only reach for profilers when the problem is clearly performance- or memory-related
For performance, start broad then zoom in — use cProfile to find the slow function, then line-profiler to find the slow line
Use py-spy when you can't modify the code — running process, production, or quick triage
Place set_trace() just before the suspect line, not at the top of the function
Never add profiling decorators to production code paths — always remind the user to remove them before deploying

Tool Reference

ipdb

Interactive debugger with IPython features (tab completion, syntax highlighting).

import ipdb

ipdb.set_trace()  # Pause execution here

Read the full file on GitHub · 128 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

scripts/setup.sh 743 B runs code

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago First seen · 128 lines · 54 tokens per session scan A 561328b96cef

Subscribe to this mod's changes

py-debug is a skill published in the GitHub repository berekvolgyipeter/dotclaude (2 stars, last pushed 2d ago), licensed MIT. It adds 54 tokens to every session and 1,037 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Claude Code Debugging Languages Python agentic-ai ai-tools anthropic coding-agents developer-tools

cuopt-developer

Modify, build, test, debug, and contribute to NVIDIA cuOpt (C++/CUDA, Python, server, CI). Use for solver internals, PRs, DCO, and code conventions.

NVIDIA/skills · 47 tokens

python-memory-safe-scripts

Memory-safe Python script patterns for long-running processes under systemd MemoryMax constraints. Covers allocator purge (mimalloc/glibc malloctrim), HTTP response lifecycle, DataFrame cleanup, thread-local connection reuse, and periodic GC cadence. Battle-tested through 5 OOM optimization cycles on production GPU…

terrylica/cc-skills · 197 tokens

py-debug