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Python Code Samples

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12 matches
Lists & loops easy

Find Most Active Contributors in a Repository with Python

Filter recent commits by date and count the most active contributors using Counter and datetime.

collections datetime counter
Python
from collections import Counter
from datetime import datetime, timedelta

# Simulated commit data
commits = [
    {"author": "Alice", "timestamp": datetime.now() - timedelta(days=1)},
    {"author": "Bob", "timestamp": datetime.now() - timedelta(days=2)},
    {"author": "Alice", "timestamp": datetime.now() - timedelta…
45 0 Open
OOP & classes easy

How to Build an In-Memory CRUD Repository Class in Python

Define a Python Repository class that stores objects in a dictionary and supports create, read, update, delete, and list operations.

repository crud oop
Python
class Repository:
    def __init__(self):
        self._data = {}

    def create(self, key, value):
        self._data[key] = value
        return key

    def read(self, key):
        return self._data.get(key)

    def update(self, key, value):
        if key not in self._data:
            raise KeyError(f"Key '{ke…
14 0 Open
Git + Python easy

Amend Last Commit Message in Python

This script uses subprocess to run `git commit --amend` and update the most recent commit's message in your repository.

git subprocess automation
Python
import subprocess
import sys


def amend_last_commit_message(new_message: str) -> None:
    """Change the message of the most recent commit."""
    result = subprocess.run(
        ["git", "commit", "--amend", "-m", new_message],
        capture_output=True,
        text=True,
        check=False,
    )
    if result.…
14 0 Open
Git + Python easy

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.

git secrets history
Python
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": …
10 0 Open
Git + Python easy

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.

git backup subprocess
Python
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…
12 0 Open
Git + Python easy

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.

git subprocess automation
Python
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:
     …
11 0 Open
Git + Python easy

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.

git revert mock
Python
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):
    …
13 0 Open
Git + Python easy

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.

git subprocess automation
Python
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…
12 0 Open
Modern tooling easy

How to List Pre-commit Hooks from YAML Config in Python

Parse a .pre-commit-config.yaml file with PyYAML and print every hook ID paired with its source repository.

pre-commit yaml pyyaml
Python
import yaml

pre_commit_config = """
repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.5.0
    hooks:
      - id: trailing-whitespace
      - id: end-of-file-fixer
      - id: check-yaml
  - repo: https://github.com/psf/black
    rev: 23.11.0
    hooks:
      - id: black
"""

def list_hooks(c…
15 0 Open
System design patterns easy

How to Implement the Repository Pattern in Python with an In-Memory Dict

Stores, retrieves, updates, and deletes user records in memory using a Repository abstraction over a plain dict, isolating data access from business logic.

repository-pattern design-patterns in-memory
Python
class UserRepository:
    def __init__(self):
        self._storage = {}
        self._next_id = 1

    def create(self, name, email):
        user_id = self._next_id
        self._next_id += 1
        self._storage[user_id] = {"id": user_id, "name": name, "email": email}
        return self._storage[user_id]

    def…
11 0 Open
System design patterns easy

How to mock the domain center in an onion architecture in Python

Define a repository interface and an in-memory mock to test domain services without touching infrastructure.

onion-architecture repository-pattern dependency-injection
Python
from abc import ABC, abstractmethod
from dataclasses import dataclass
from typing import Dict, List, Optional


@dataclass
class Order:
    id: int
    customer: str
    items: List[str]
    total: float


class OrderRepository(ABC):
    @abstractmethod
    def find_by_id(self, order_id: int) -> Optional[Order]:
     …
11 0 Open
API design & gRPC easy

How to Mock a GraphQL Query Type in Python

Create a lightweight mock of a GraphQL Query type to simulate repository lookups without a server.

graphql mock resolver
Python
import json

class Query:
    def __init__(self):
        self.starred_repos = [
            {"id": 1, "name": "graphql", "owner": "graphql"}
        ]

    def repository(self, name):
        if name == "graphql":
            return {"id": 1, "name": "graphql", "stargazerCount": 85000}
        return None


if __name…
14 0 Open

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