python-performance-optimization

A workflow for measuring and improving the performance of Python programs. It uses CPU and memory profiling to find slow functions, high memory use, leaks, and inefficient input/output or database work.

In plain words
What is it for?
Use it to profile Python applications, locate bottlenecks, reduce memory consumption, improve database and input/output operations, and optimize algorithms.
Why use it?
It replaces guesswork with measurements of where time and memory are actually being spent. This helps target changes that reduce latency, resource use, or processing time.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/cognicellai/cognition/python-performance-optimization
Any agent
npx skills add CognicellAI/Cognition --skill python-performance-optimization
Clone the repo
git clone --depth 1 https://github.com/CognicellAI/Cognition

Made for: Claude Code, Codex.

Per session 40 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,387 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00040 $0.05387
Opus 5 $0.00020 $0.02694
Sonnet 5 $0.00008 $0.01077
Haiku 4.5 $0.00004 $0.00539

Measured yesterday against content hash 485203c990c3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

python-performance-optimization scanned grade A with 1 finding 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 yesterday.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

response = requests.get(url)
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.agents/skills/python-performance-optimization/SKILL.md · 875 lines

How it starts

The opening of the file, as written. The whole thing — 875 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Python Performance Optimization

Comprehensive guide to profiling, analyzing, and optimizing Python code for better performance, including CPU profiling, memory optimization, and implementation best practices.

When to Use This Skill

  • Identifying performance bottlenecks in Python applications
  • Reducing application latency and response times
  • Optimizing CPU-intensive operations
  • Reducing memory consumption and memory leaks
  • Improving database query performance
  • Optimizing I/O operations
  • Speeding up data processing pipelines
  • Implementing high-performance algorithms
  • Profiling production applications

Core Concepts

1. Profiling Types

  • CPU Profiling: Identify time-consuming functions
  • Memory Profiling: Track memory allocation and leaks
  • Line Profiling: Profile at line-by-line granularity
  • Call Graph: Visualize function call relationships

2. Performance Metrics

  • Execution Time: How long operations take
  • Memory Usage: Peak and average memory consumption
  • CPU Utilization: Processor usage patterns
  • I/O Wait: Time spent on I/O operations

3. Optimization Strategies

  • Algorithmic: Better algorithms and data structures
  • Implementation: More efficient code patterns
  • Parallelization: Multi-threading/processing
  • Caching: Avoid redundant computation
  • Native Extensions: C/Rust for critical paths

Quick Start

Basic Timing

import time

def measure_time():
    """Simple timing measurement."""
    start = time.time()

    # Your code here
    result = sum(range(1000000))

    elapsed = time.time() - start
    print(f"Execution time: {elapsed:.4f} seconds")
    return result

# Better: use timeit for accurate measurements
import timeit

execution_time = timeit.timeit(
    "sum(range(1000000))",
    number=100
)
print(f"Average time: {execution_time/100:.6f} seconds")

Profiling Tools

Pattern 1: cProfile - CPU Profiling

import cProfile
import pstats
from pstats import SortKey

def slow_function():
    """Function to profile."""
    total = 0
    for i in range(1000000):
        total += i
    return total

def another_function():
    """Another function."""
    return [i**2 for i in range(100000)]

def main():
    """Main function to profile."""
    result1 = slow_function()
    result2 = another_function()
    return result1, result2

# Profile the code
if __name__ == "__main__":
    profiler = cProfile.Profile()
    profiler.enable()

    main()

    profiler.disable()

    # Print stats
    stats = pstats.Stats(profiler)
    stats.sort_stats(SortKey.CUMULATIVE)
    stats.print_stats(10)  # Top 10 functions

    # Save to file for later analysis
    stats.dump_stats("profile_output.prof")

Read the full file on GitHub · 875 lines

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.

  1. yesterday First seen · 875 lines · 40 tokens per session scan A 485203c990c3

Subscribe to this mod's changes

python-performance-optimization is a skill published in the GitHub repository CognicellAI/Cognition (10 stars, last pushed 14d ago), licensed MIT. It adds 40 tokens to every session and 5,387 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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