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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 Squash Commits Range into One in Python
A mock script that displays the last N git commits as a single squashed commit, showing original commit subjects.
import subprocess
import re
def squash_last_commits(count):
"""Mock squashing the last N commits into one by display."""
git_log = subprocess.run(
["git", "log", f"-{count}", "--pretty=format:%h %s"],
capture_output=True, text=True
)
if git_log.returncode != 0:
return "Git comm…
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…
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…
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 Cloud Cost Estimates with a Python Dictionary
Mocks a cloud pricing calculator using a dictionary of service rates and computes total estimated cost for given service hours.
def estimate_cost(service, hours, rate_table=None):
if rate_table is None:
rate_table = {
"basic": 50,
"standard": 75,
"premium": 100
}
if service not in rate_table:
raise ValueError(f"Unknown service: {service}")
return rate_table[service] * hour…
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 Check an SCP Deny List in Python
Load a JSON SCP policy file, extract the deny_list, and check if a target ARN is denied.
import json
from pathlib import Path
def evaluate_scp_deny_list(policy_path: Path, target_path: str) -> bool:
policy = json.loads(policy_path.read_text())
deny_list = policy.get("deny_list", [])
return target_path in deny_list
if __name__ == "__main__":
policy_file = Path("scp_policy.json")
pol…
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…
How to Enforce Tag Policies on AWS Resources in Python
Build a reusable Python class that checks AWS resources against a required-tag policy and reports compliance with missing tags.
import json
from dataclasses import dataclass, field
from typing import Dict, List
@dataclass
class Resource:
arn: str
tags: Dict[str, str] = field(default_factory=dict)
class TagPolicyEnforcer:
def __init__(self, required_tags: List[str]):
self.required_tags = set(required_tags)
def enfor…
How to Evaluate Mock NACL Rules in Python
Simulate numbered AWS Network ACL rule evaluation with HMAC integrity checks on request payloads.
import base64
import json
import hmac
import hashlib
def evaluate_mock_rule(rule_number, request_data, secret):
"""
Simulates evaluating an NACL-like numbered rule by:
1. Checking if the rule number exists in the mock policy.
2. Computing an HMAC over the request payload for integrity.
"""
# M…
How to Generate a Mock EKS Kubeconfig in Python
Generate a minimal kubeconfig dict with a mock EKS cluster entry and dump it to YAML using PyYAML.
import yaml
from pathlib import Path
def mock_eks_kubeconfig(cluster_name: str) -> dict:
"""Return a minimal kubeconfig dict with a mock EKS cluster entry."""
return {
"apiVersion": "v1",
"kind": "Config",
"clusters": [
{
"name": f"arn:aws:eks:us-east-1:123…
How to Implement Region Failover Config in Python with Primary and Secondary Mock
This Python class simulates regional failover: it tracks active region, switches to secondary on primary failure, and allows manual recovery.
import time
class RegionFailoverConfig:
def __init__(self, primary, secondary):
self.primary = primary
self.secondary = secondary
self.active = primary
self.failover_count = 0
self.healthy = True
def check_health(self):
"""Mock health check - returns True if ac…
How to Implement Retry with Exponential Backoff for Cloud API 429 Errors in Python
Implement a retry-with-backoff loop in Python to handle 429 throttling errors from cloud APIs, using exponential delay between attempts.
import time
import random
import requests
def api_call(attempt):
"""Mock cloud API that returns 429 for the first two attempts."""
if attempt < 2:
return 429, "Too Many Requests"
return 200, {"data": "success"}
def retry_with_backoff(api_func, max_retries=3, base_delay=0.1):
for attempt in …
How to Mock AWS Secrets Manager in Python
Create a lightweight mock of AWS Secrets Manager's get_secret_value API to test secret retrieval without cloud dependencies.
import json
from typing import Optional
class MockSecretsManager:
"""A simple mock of AWS Secrets Manager's get_secret_value API."""
def __init__(self):
self._secrets: dict[str, str] = {}
def create_secret(self, secret_id: str, secret_value: str) -> None:
"""Store a secret value under a…
How to Mock Auto Scaling Policy Scale Out in Python
Define a mock auto-scaling function that scales out capacity by a factor up to a max, simulating AWS-like events.
def mock_scale_out(current_capacity: int, max_capacity: int, scale_factor: int = 1) -> tuple:
"""
Mock auto-scaling policy: scales out by the specified factor
if capacity allows, capped at max_capacity.
"""
if current_capacity >= max_capacity:
return current_capacity, False
new_cap…
How to Mock Azure Service Bus Queue in Python
A lightweight in-memory mock of the Azure Service Bus queue API for local testing without cloud dependencies.
import json
import time
from collections import deque
class ServiceBusQueueMock:
def __init__(self, queue_name):
self.queue_name = queue_name
self._messages = deque()
self._dead_letter_queue = deque()
self._message_counter = 0
def send_message(self, body, message_id=None, prop…
How to Mock CloudFront Invalidation Paths in Python
Build a sorted, deduplicated list of CloudFront invalidation paths from a set of file paths, adding implicit index.html entries.
import argparse
def build_invalidation_paths(files, include_index=True):
"""
Create CloudFront invalidation paths from a list of files.
Converts file names to root-relative paths and optionally adds /index.html.
"""
paths = []
for f in files:
f = f.strip()
if not f:
…
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