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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 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 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 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 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…
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…
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, …
How to Test Hypotheses with Property-Based Check in Python
A Python search that checks an integer property (palindrome divisible by digit sum) and returns the first counterexample within a range, with exactly reproduced output from the code.
def is_property_satisfied(n):
"""
Demonstrates a mathematically inspired property:
checks whether n is both a palindrome and divisible by its digit sum.
"""
s = str(n)
if s != s[::-1]:
return False
digit_sum = sum(int(d) for d in s)
return digit_sum != 0 and n % digit_sum == 0
…
How to Attach an SBOM to a Release in Python (Mock)
A mock function that attaches a Software Bill of Materials (SBOM) to a GitHub-style release by counting its components and marking the upload as attached.
import json
from pathlib import Path
def attach_sbom_mock(sbom_path: Path, release_tag: str, artifact_name: str) -> dict:
"""Mock attaching an SBOM to a release, returning the simulated upload result."""
sbom = json.loads(sbom_path.read_text())
return {
"release_tag": release_tag,
"artifa…
How to Mock a GitHub Actions Workflow in Python
Build a dataclass-based model of a GitHub Actions workflow and simulate its execution to validate steps and outputs before deployment.
import json
from dataclasses import dataclass, asdict
from typing import List, Dict, Any
@dataclass
class Step:
name: str
run: str
@dataclass
class Job:
name: str
steps: List[Step]
runs_on: str = "ubuntu-latest"
@dataclass
class Workflow:
name: str
jobs: List[Job]
def to_github_a…
How to simulate GitLab CI stages in Python
Build a lightweight Python mock of GitLab CI pipeline stages to test job sequencing and output locally.
def mock_gitlab_ci_stages():
stages = ["build", "test", "deploy"]
stage_status = {}
for stage in stages:
jobs = []
if stage == "build":
jobs = ["compile", "package"]
elif stage == "test":
jobs = ["unit", "integration", "e2e"]
elif stage == "deploy":…
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