Python Code
Samples
Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to Generate a Dependency Graph for Python Projects
This script walks through a Python project directory, parses each .py file's imports, and prints a dependency graph showing which modules depend on which other modules.
import os
import ast
from pathlib import Path
from collections import defaultdict
def get_imports(filepath):
with open(filepath) as f:
try:
tree = ast.parse(f.read())
except SyntaxError:
return []
imports = []
for node in ast.walk(tree):
if isinstance(node, …How to Monitor Laptop Battery Health Over Time in Python
Log battery percentage, power status, and remaining time every N seconds to a JSON file using psutil for ongoing health monitoring.
import time
import json
from pathlib import Path
from datetime import datetime
try:
import psutil
except ImportError:
print("psutil required: pip install psutil")
exit(1)
LOG_FILE = Path("battery_health_log.json")
def monitor_battery(log_interval=60, duration=300):
"""Log battery percentage and rema…How to Monitor Process RSS Memory in Python
Poll the VmRSS field from /proc/PID/status to watch a process's resident memory and alert on growth.
import os
import time
import subprocess
import sys
def get_rss_mb(pid):
"""Return RSS memory in MB for a given process ID."""
try:
with open(f"/proc/{pid}/status", "r") as f:
for line in f:
if line.startswith("VmRSS:"):
return int(line.split()[1]) / 1024…How to Save a VM Snapshot State to a JSON File in Python
Define a dataclass for a VM snapshot and serialize it to a JSON file, then reload it to verify the state.
import json
from dataclasses import dataclass, asdict
from pathlib import Path
@dataclass
class VMSnapshot:
name: str
memory_mb: int
disk_gb: int
state: str = "saved"
def snapshot_to_file(self, path: Path) -> str:
"""Write snapshot state to a JSON file and return the filename."""
…How to check Python files for common coding mistakes
Walks a directory tree parsing each .py file with ast, reporting empty functions, bare try blocks, too many parameters, and empty classes.
import ast
import os
import sys
def check_file(filepath):
try:
with open(filepath) as f:
code = f.read()
tree = ast.parse(code, filename=filepath)
except SyntaxError as e:
print(f"{filepath}: SyntaxError: {e.msg}")
return
issues = []
for node in ast.wal…How to generate website performance reports from HTTP requests in Python
Measure and report website load time, status code, and content size using Python's standard library.
import urllib.request
import time
def measure_website_load_time(url):
"""Measures total loading time of a website."""
start_time = time.time()
try:
with urllib.request.urlopen(url, timeout=10) as response:
content = response.read()
status_code = response.status
…Mock systemctl Wrapper in Python for Service Testing
A Python class-based mock of systemctl that simulates start, stop, restart, and status operations for a service, useful for testing automation scripts.
import subprocess
import sys
class ServiceManager:
def __init__(self, service_name):
self.service_name = service_name
self.status = "inactive"
def start(self):
self.status = "active"
print(f"Starting {self.service_name}... OK")
def stop(self):
self.status …Monitor Website Uptime with Python
Periodically check if a website is reachable and its HTTP status is 200, logging the status with timestamps.
import requests
import time
def check_website(url):
try:
response = requests.get(url, timeout=5)
if response.status_code == 200:
return True
else:
return False
except requests.ConnectionError:
return False
except requests.Timeout:
return Fals…Port Scan Localhost Common Ports in Python
Scan common localhost ports (HTTP, HTTPS, SSH, FTP, and more) with a fast socket-based Python script that prints an open/closed status table.
import socket
from datetime import datetime
COMMON_PORTS = {
80: "HTTP",
443: "HTTPS",
22: "SSH",
21: "FTP",
25: "SMTP",
3306: "MySQL",
5432: "PostgreSQL"
}
def scan_port(port):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.settimeout(0.1)
try:
resu…Scrape HTML Tables in Python with html.parser
Extract data from HTML tables using Python's built-in html.parser module, without third-party dependencies, by overriding callback methods to track table, row, and cell states.
import html.parser
from urllib.request import urlopen
class TableParser(html.parser.HTMLParser):
def __init__(self):
super().__init__()
self.in_table = False
self.in_row = False
self.in_cell = False
self.current_cell = []
self.rows = []
self.row = []
d…Toggle VPN Mock Network Manager Script in Python
Simulate a VPN manager with connect, disconnect, toggle, and status methods for testing or demo workflows.
import time
class MockVPNManager:
def __init__(self):
self.is_connected = False
self.servers = ["us-west", "eu-central", "asia-east"]
self.active_server = None
def toggle(self):
if self.is_connected:
self.disconnect()
else:
self.connect()
d…How to Implement a Sliding Window Average in Python
Compute the average of the most recent N values in a stream using a bounded deque, efficiently updating the total as new values arrive.
from collections import deque
class SlidingWindowAverage:
def __init__(self, window_size):
self.window_size = window_size
self.window = deque(maxlen=window_size)
self.total = 0
def add(self, value):
if len(self.window) == self.window_size:
self.total -= self.windo…How to detect anomalies in a column using z-score in Python
Detect outliers in a list of numbers using z-score statistics, flagging values that deviate significantly from the mean.
import random
def z_score_anomaly_detection(data, threshold=2.0):
"""
Detect anomalies in a list of numbers using z-score.
"""
mean = sum(data) / len(data)
variance = sum((x - mean) ** 2 for x in data) / len(data)
std_dev = variance ** 0.5
if std_dev == 0:
return []
a…Get Git Status Info in Python
Run git commands from Python to gather branch name, number of changes, total commits, and clean status, returning them as a dict.
import subprocess
import json
from pathlib import Path
def get_git_status(repo_path="."):
"""Return basic git info about a repository as a dict."""
try:
branch = subprocess.check_output(
["git", "branch", "--show-current"],
cwd=repo_path,
stderr=subprocess.DEVNULL,…How to Build a Git Helper Class in Python
A beginner-friendly GitHelper class that wraps common git commands (status, log, branch) into reusable Python methods with structured output.
import subprocess
import json
from pathlib import Path
class GitHelper:
def __init__(self, repo_path="."):
self.repo = Path(repo_path)
def run(self, *args):
result = subprocess.run(
["git", *args],
cwd=self.repo,
capture_output=True,
text=True,…How to Get Git Status and Log in Python
A beginner-friendly helper that runs git status and git log from Python using subprocess, with safe handling for non-repo directories.
import subprocess
from pathlib import Path
def git_status(path: str = ".") -> str:
"""Return the current git status as a string."""
result = subprocess.run(
["git", "status", "--short"],
cwd=path,
capture_output=True,
text=True
)
return result.stdout.strip() or "No cha…How to Mock Git Worktree Creation in Python
Create a mock Git worktree setup with parallel branch directories and state files for testing or simulation.
import os
import tempfile
from pathlib import Path
def create_mock_worktree(base_dir: Path, branches: list[str]) -> dict[str, Path]:
"""
Mock Git worktree creation: creates parallel directories for each branch
under the base directory, simulating independent worktrees.
"""
worktrees = {}
for b…How to Parse git status --porcelain Output in Python
This code runs `git status --porcelain` and parses its output into a list of dictionaries with file paths and status descriptions.
import subprocess
def parse_git_status_porcelain():
try:
output = subprocess.check_output(
["git", "status", "--porcelain"],
text=True,
stderr=subprocess.DEVNULL
)
except (subprocess.CalledProcessError, FileNotFoundError):
return []
entries = …How to Run Git Commands from Python with subprocess
This helper runs `git status --short` and `git log --oneline` from Python, captures their output, and returns readable strings with error handling for non-repo directories.
import subprocess
def git_status():
"""Return a short, human-readable git status."""
try:
output = subprocess.run(
["git", "status", "--short"],
capture_output=True,
text=True,
check=True,
).stdout.strip()
return output if output else "W…How to Stage All Modified Files with git add -u in Python
Runs git add -u from Python to stage all modified and deleted tracked files, then prints the short status.
import subprocess
def stage_all_modified_files(repo_path="."):
"""Run git add -u to stage all modified and deleted tracked files."""
result = subprocess.run(
["git", "add", "-u"],
cwd=repo_path,
capture_output=True,
text=True,
)
if result.returncode != 0:
print…How to compute diff stats (insertions, deletions) in Python
Parses a git diff text and counts the number of added and removed lines to produce insertion and deletion stats.
import re
from collections import Counter
def parse_diff(diff_text):
insertions = 0
deletions = 0
for line in diff_text.splitlines():
if line.startswith("+") and not line.startswith("+++"):
insertions += 1
elif line.startswith("-") and not line.startswith("---"):
d…Generate Mock CloudFormation Stack Events in Python
Generate a list of mock AWS CloudFormation stack events with random resources, statuses, and timestamps, and print them as JSON.
import json
import random
from datetime import datetime, timedelta
def generate_mock_stack_events(stack_name="MyTestStack", num_events=10):
"""Generate a list of mock CloudFormation stack events."""
resources = [
("AWS::S3::Bucket", "MyBucket"),
("AWS::EC2::Instance", "MyInstance"),
("…How to Mock ELB Target Health Status in Python
Simulate AWS Elastic Load Balancer target health checks with a Python dict that mutates status and healthy host counts.
from random import randint
def elb_target_mock_status(target_id, healthy=True):
targets = {
1: {"Id": "i-001", "Status": "healthy", "Port": 80, "HealthyHostCount": 1},
2: {"Id": "i-002", "Status": "unhealthy", "Port": 80, "HealthyHostCount": 0},
3: {"Id": "i-003", "Status": "healthy", "Por…How to mock boto3 S3 upload in Python
Shows how to mock the boto3 S3 client with unit tests and wrap an upload function to return a dictionary with status details.
import boto3
from unittest.mock import Mock, patch
class S3Uploader:
def __init__(self, bucket_name):
self.bucket_name = bucket_name
self.s3 = boto3.client("s3", region_name="us-east-1")
def upload_file(self, local_path, s3_key):
self.s3.upload_file(local_path, self.bucket_name, s3_ke…Browse by section
Each section groups closely related Python snippets.
Guide: free Python code samples library
Copy-ready Python snippets for learners and developers
PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.
How to use this library
- Pick a topic section — strings, lists, files, functions, and more
- Open a sample, read How it works, and copy the code block
- Run it in the IDE, tweak values, then take a related quiz or tutorial lesson
Samples vs tutorials and challenges
Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.