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How to Run a Mock Cron Pipeline Scheduler in Python
This code schedules a mock pipeline job to run every 2 seconds and hourly at :30 using the schedule library, then runs pending tasks for 10 seconds.
import time
import schedule
from datetime import datetime
def run_pipeline():
print(f"{datetime.now().strftime('%Y-%m-%d %H:%M:%S')} - Pipeline executed")
schedule.every(2).seconds.do(run_pipeline)
schedule.every().hour.at(":30").do(run_pipeline)
print("Scheduler started. Press Ctrl+C to stop.")
end_time = ti…How to perform a star schema join in Python
Denormalize mock fact and dimension tables by building lookup dicts and enriching each sales fact with customer, product, and date attributes.
from datetime import date
# Mock dimension tables
customers = [
{"customer_id": 1, "name": "Alice", "city": "New York"},
{"customer_id": 2, "name": "Bob", "city": "Los Angeles"},
{"customer_id": 3, "name": "Carol", "city": "Chicago"},
]
products = [
{"product_id": 101, "name": "Laptop", "category": "…Implement Exactly-Once Transaction Log in Python
A mock transaction log that deduplicates transaction IDs so each is recorded only once, with a dataclass for records and simple in-memory storage.
from dataclasses import dataclass
from typing import Dict, Optional
@dataclass
class TxnRecord:
txn_id: str
status: str
class ExactlyOnceTxnLog:
def __init__(self) -> None:
self._log: Dict[str, TxnRecord] = {}
self._processed_ids: set = set()
def record(self, txn_id: str, status: s…Map Partition Over Chunks in Python with Multiprocessing and Mock
Process data in chunks across multiple CPU cores using multiprocessing Pool.map, and mock the chunk function to test partitioning behavior without heavy computation.
from multiprocessing import Pool
from unittest.mock import patch, Mock
def process_chunk(chunk):
return [x * x for x in chunk]
def map_partition_over_chunks(data, chunk_size, process_func=process_chunk):
chunks = [data[i:i + chunk_size] for i in range(0, len(data), chunk_size)]
with Pool() as pool:
…Create a Mock GitHub Release API in Python for Testing gh CLI
Build an in-memory GitHub Releases API mock that mimics create_release and list_releases for unit testing gh CLI stubs without network calls.
import json
from unittest.mock import patch, Mock
class GitHubReleaseAPI:
"""Mock GitHub Releases API for testing gh CLI stub behavior."""
def __init__(self):
self.releases = {}
self.counter = 1
def create_release(self, repo, tag, name=None, notes=None):
release_id = self…Git Signing in Python
Sign and verify Git commits with a mock GPG implementation using HMAC and SHA-256.
import hashlib
import hmac
class GPGMock:
def __init__(self, secret_key):
self.secret_key = secret_key.encode()
def sign_commit(self, commit_message):
"""Mock GPG signing by computing an HMAC of the commit message."""
signature = hmac.new(self.secret_key, commit_message.encode(), hash…How to Archive a Repository as a ZIP in Python
Create a ZIP archive of a repository directory with a mock export, skipping hidden files and __pycache__ folders.
import zipfile
import io
import os
from pathlib import Path
def archive_repo_mock(repo_path, output_path="repo_archive.zip"):
"""Create a zip archive of a repository directory (mock export)."""
repo = Path(repo_path)
if not repo.exists():
raise FileNotFoundError(f"Repository not found: {repo}")
…How to Build a Branch Protection Audit Mock API in Python
A mock HTTP API that serves branch protection rules for repositories and audits them for compliance, built with Python's standard library.
import json
from http.server import BaseHTTPRequestHandler, HTTPServer
from urllib.parse import urlparse, parse_qs
REPOSITORIES = {
"alpha": {
"default_branch": "main",
"branches": ["main", "develop", "feature-x"],
"protection_rules": {
"main": {"required_reviews": 2, "dismiss_…How to Filter Git History to Remove Secret File Entries in Python
A pure-Python mock that filters a repository's history to drop any commit that touched a secret file, so you can plan a cleanup before rewriting Git history.
from pathlib import Path
import json
def filter_history(history, secret_path):
"""Remove entries that touch the secret file."""
return [entry for entry in history if secret_path not in entry["files"]]
if __name__ == "__main__":
repo_history = [
{"commit": "a1b2c3", "message": "Add app", "files": …How to Generate Git LFS Extension Patterns in Python
This script builds mock Git LFS file patterns for common geospatial extensions and filters them based on compression suffixes.
import itertools
import re
LFS_EXTENSIONS = {".csv", ".geojson", ".tif", ".shp", ".gpkg"}
def build_mock_lfs_pattern(base_name="data_usgs_lidar"):
patterns = []
for ext in sorted(LFS_EXTENSIONS):
for variant in (("", ".lz4"), (".compressed",), (".b", ".a"), ("_v1", ".zip")):
full_pattern …How to Get Current Git Branch Name in Python with Mock Subprocess
Mocks the subprocess call to reliably test the current git branch name retrieval using GitPython.
import subprocess
from unittest.mock import patch, MagicMock
from git import Repo
import os
def get_current_branch(repo_path="."):
"""Get the current branch name of a git repository."""
repo = Repo(repo_path)
return repo.active_branch.name
if __name__ == "__main__":
# Mock subprocess to control the…How to Mock Git Cherry-Pick in Python for Tests
Mock the `repo.git.cherry_pick` method with `unittest.mock` to test a Git cherry-pick helper without a real repository.
from unittest.mock import patch, MagicMock
class GitCherryPicker:
def __init__(self):
self.applied_commits = []
def cherry_pick(self, commit_hash, repo):
try:
result = repo.git.cherry_pick(commit_hash)
self.applied_commits.append(commit_hash)
return f"A…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 Pre-commit Hooks (black and ruff) in Python
Mock subprocess to test black and ruff pre-commit commands without actually running them, verifying exit codes.
import sys
import subprocess
from unittest.mock import patch
def run_hook(command: list[str]) -> int:
with patch("subprocess.run") as mock_run:
mock_run.return_value.returncode = 0
mock_run.return_value.stdout = f"Mocked: {' '.join(command)}"
result = subprocess.run(command, capture_output…How to Mock Git Stash and Pop in Python
Mock Git stash, apply, and pop operations using unittest.mock so you can test Git automation without touching a real repository.
import git
from unittest.mock import Mock, patch
def stash_and_pop(repo):
"""Mock a stash operation and then pop it back."""
repo.git.stash("save", "WIP: temp changes")
stashed_output = repo.git.stash("list")
# Simulate the stash was applied, then pop
repo.git.stash("apply", "stash@{0}")
…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 Mock open() in Python Using unittest.mock.patch
This code shows how to use unittest.mock.patch with mock_open to test a function that checks if a Git patch can be reverse-applied by reading file content.
import unittest
from unittest.mock import patch, mock_open
def apply_reverse_check(file_path, expected_patch):
"""
Check if a patch can be reverse-applied by comparing file content
with the expected patch's reverse result.
"""
try:
with open(file_path, "r") as f:
content = f.r…How to Mock subprocess.run in Python Tests
Mock subprocess.run to test a Git submodule update command without executing it in your test suite.
import subprocess
from unittest.mock import Mock, patch
def update_submodules():
subprocess.run(["git", "submodule", "update", "--init", "--recursive"], check=True)
with patch("subprocess.run") as mock_run:
mock_run.return_value = Mock(returncode=0)
update_submodules()
mock_run.assert_called_once_wit…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 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…Merge branch no ff mock in Python
Simulate a Git non-fast-forward merge in Python, producing a synthetic merge commit log for branches with differing SHAs.
class MergeResult:
def __init__(self, base, branch):
self.base = base
self.branch = branch
self.commit_log = []
self.merged = False
def simulate_merge(self):
"""Simulate a 'no-ff' merge by creating a new commit that references both branches."""
if self.base == s…Mock smtplib to Test Patch Email Series in Python
Simulate sending a numbered series of patch emails with smtplib and verify the calls using unittest.mock without a real mail server.
import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from unittest.mock import patch, Mock
def send_patch_series(subject_prefix, patches, smtp_host="localhost", smtp_port=25):
"""Simulate sending a series of patch emails."""
for i, patch_content in enumerate(patch…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…Browse by section
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