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How to List Changed Files in the Last Git Commit with Python
Runs `git diff --name-only HEAD~1 HEAD` via subprocess to list the names of files changed in the most recent commit.
import subprocess
def list_changed_files():
result = subprocess.run(
["git", "diff", "--name-only", "HEAD~1", "HEAD"],
capture_output=True,
text=True,
check=True
)
files = result.stdout.strip().splitlines()
return files
if __name__ == "__main__":
changed = list_cha…How to Make a Shallow Clone of an Object in Python
Demonstrates using copy.copy() to create a shallow clone of a Python object, showing how nested mutable data is shared while top-level attributes are independent.
import copy
class Config:
def __init__(self):
self.settings = {"volume": 50}
self.user = "admin"
def demonstrate_shallow_copy():
original = Config()
shallow = copy.copy(original)
# Mutating nested object is visible in both (shallow copy share it)
shallow.settings["volume"] = 90…How to Mirror a Bare Git Repository Backup in Python
Run a git clone --bare subprocess to create a timestamped bare-repo backup folder with error handling.
import subprocess
import shlex
from pathlib import Path
from datetime import datetime
def mirror_bare_repo(source_url: str, backup_dir: str) -> str:
"""Mirror a bare git repository to a timestamped backup folder."""
backup_path = Path(backup_dir)
backup_path.mkdir(parents=True, exist_ok=True)
timest…How to Mock Git Clean Dry Run in Python
Simulate the output of `git clean -n` in Python to preview which untracked files would be removed without actually deleting them.
import subprocess
import sys
def mock_git_clean_dry_run(untracked_files):
"""Simulate `git clean -n` for a given list of untracked files."""
if not untracked_files:
print("No untracked files to remove.")
return
print("Would remove:")
for file in untracked_files:
print(f" {fil…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 Mock git sparse-checkout Paths in Python
Simulates git sparse-checkout configuration by writing desired paths to the sparse-checkout file without running git commands.
import subprocess
from pathlib import Path
import tempfile
def configure_sparse_checkout(repo_dir: Path, paths: list[str]) -> list[str]:
"""Simulate sparse checkout configuration by returning the paths that would be set."""
sparse_checkout_file = repo_dir / ".git" / "info" / "sparse-checkout"
sparse_chec…How to Push Git Tags to a Remote with Python
Push specified git tags (or all tags) to a remote repository using Python's subprocess module with error handling.
import subprocess
import sys
def push_tags_to_remote(remote: str = "origin", tags: list[str] | None = None) -> None:
"""
Push git tags to a remote repository.
If no tags are given, push all local tags.
"""
if tags:
subprocess.run(["git", "push", remote, *tags], check=True)
else:
…How to Revert a Commit and Create a New Revert Commit in Python
Demonstrates a mock Git repository that creates a new revert commit on top of the current head when reverting an existing commit.
class GitCommit:
"""Minimal mock of a git commit for demonstrating revert behavior."""
def __init__(self, sha, message):
self.sha = sha
self.message = message
self.parent = None
class GitRepository:
"""Mock repository tracking a simple commit chain."""
def __init__(self):
…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 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…How to detect secrets in git history with Python
Scan a git history export file for common secret patterns using regex and Python.
import re
from pathlib import Path
def scan_history_for_secrets(history_file: str) -> list:
"""Scan a git history export for potential secrets using regex patterns."""
patterns = {
"AWS Access Key": r"AKIA[0-9A-Z]{16}",
"GitHub Token": r"gh[pousr]_[0-9A-Za-z]{36,255}",
"Private Key": …How to sync a fork with upstream in Python
Run git fetch and merge commands from Python with subprocess to sync a forked repository with upstream/main.
import subprocess
import sys
def sync_fork_with_upstream():
"""Simulate syncing a forked repo with upstream via git commands."""
# Mock git operations: pretend to fetch from upstream and merge into main
fetch_result = subprocess.run(
["git", "fetch", "upstream"],
capture_output=True, tex…Upload Assets to GitHub Release with Python Mock
Simulates uploading binary and text assets to a GitHub release using a mock server, returning structured metadata for each upload.
import json
import os
import tempfile
from datetime import datetime
class ReleaseUploader:
"""Simulates uploading assets to a release with a mock server."""
def __init__(self, owner: str, repo: str, tag: str):
self.owner = owner
self.repo = repo
self.tag = tag
self.uploade…Verify Git tag signatures with HMAC in Python
Create and verify deterministic HMAC-SHA256 signatures for git tags using the Python standard library.
import hashlib
import hmac
def sign_tag(tag: str, secret_key: str) -> str:
"""Create a deterministic HMAC signature for a tag."""
message = tag.encode("utf-8")
key = secret_key.encode("utf-8")
return hmac.new(key, message, hashlib.sha256).hexdigest()
def verify_signed_tag(tag: str, signature: str, …Create a Cloud Storage Helper Class in Python
Build a simple local file-based helper class that mimics cloud storage operations like save, load, and list JSON objects.
import datetime
import json
from pathlib import Path
class CloudDataHelper:
"""Simple helper for reading/writing JSON files in a cloud-style folder."""
def __init__(self, base_dir: str = "cloud_storage"):
self.base_dir = Path(base_dir)
self.base_dir.mkdir(exist_ok=True)
def save_json(se…Create a Data Helper Class for Beginners in Python
A simple Python class to read and write JSON and CSV files from a local directory, ideal for automating data workflows in cloud environments.
import json
from pathlib import Path
class DataHelper:
"""Simple helper for reading and writing common data files."""
def __init__(self, directory="data"):
self.directory = Path(directory)
self.directory.mkdir(exist_ok=True)
def save_json(self, filename, data):
filepath =…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 Build a Budget Alert Threshold with Mock Notifications in Python
This code calculates budget usage percentage and triggers a mock alert notification when the usage exceeds a defined threshold.
budget = 500.0
spent = 620.0
alert_threshold = 0.8
def mock_notify(percent_used):
if percent_used >= alert_threshold:
return f"ALERT: Budget usage at {percent_used * 100:.1f}% — over {alert_threshold * 100:.0f}% threshold!"
return f"OK: Budget usage at {percent_used * 100:.1f}% — under threshold."
pe…How to Build a Multi-Cloud Config Loader with Provider Switching in Python
Load cloud provider configurations (AWS, Azure, GCP) from JSON files using a provider dispatch pattern in Python.
import json
from pathlib import Path
from dataclasses import dataclass
from typing import Dict, Any
@dataclass
class CloudConfig:
provider: str
region: str
settings: Dict[str, Any]
class ConfigLoader:
def __init__(self, config_dir: str = "configs"):
self.config_dir = Path(config_dir)
…How to Calculate VPC Subnet CIDR Details in Python
Compute network address, broadcast address, address count, prefix length, and netmask for any IPv4 CIDR using the Python standard library's ipaddress module.
import ipaddress
def subnet_details(cidr: str) -> dict:
network = ipaddress.ip_network(cidr, strict=False)
return {
"network_address": str(network.network_address),
"broadcast_address": str(network.broadcast_address),
"num_addresses": network.num_addresses,
"prefix_length": ne…How to Convert Python Dict to JSON and Back
Convert Python dictionaries to JSON text and back with a simple helper that serializes and deserializes data structures.
import json
from datetime import datetime, timezone
def convert_data(data, source_format=None, target_format="json"):
"""
Convert Python data structures to txt/json and back.
For beginners: shows how to serialize/deserialize.
"""
if source_format == "json" and target_format == "dict":
ret…How to Create a JSON Data Helper in Python
A beginner-friendly DataHelper class that safely reads and writes JSON files with timestamps to a local data directory.
from datetime import datetime
from pathlib import Path
import json
class DataHelper:
"""Simple helper for reading/writing JSON files safely."""
def __init__(self, base_dir="data"):
self.base_dir = Path(base_dir)
self.base_dir.mkdir(exist_ok=True)
def save(self, filename, data):
…How to Create a Mock STS AssumeRole Credentials Dict in Python
Build a realistic AWS STS AssumeRole response dict with temporary credentials, expiry time, and assumed role ARN for local testing.
import json
from datetime import datetime, timedelta, timezone
def mock_sts_credentials(role_arn, session_name, duration=3600):
now = datetime.now(timezone.utc)
expiration = now + timedelta(seconds=duration)
credentials = {
"Credentials": {
"AccessKeyId": "ASIAEXAMPLEACCESSKEY",
…How to Design a Cloud Data Helper Class in Python
A beginner-friendly Python helper class that saves, loads, and aggregates JSON records locally, simulating cloud-style data handling.
import json
from pathlib import Path
from datetime import datetime
class CloudDataHelper:
"""Beginner-friendly helper for working with cloud-based JSON data."""
def __init__(self, base_dir="cloud_data"):
self.base_dir = Path(base_dir)
self.base_dir.mkdir(exist_ok=True)
def save_record(s…Browse by section
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