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Python Code Samples

Easy snippets you can copy, study, and run in the browser editor.

8 matches
Lists & loops easy

How to Rotate a List in Python

Rotate a list to the right by k positions using Python's list slicing and modulo arithmetic.

list rotation slicing
Python
def rotate_list_right(lst, k):
    if not lst:
        return lst
    k = k % len(lst)
    return lst[-k:] + lst[:-k] if k != 0 else lst


if __name__ == "__main__":
    sample = [1, 2, 3, 4, 5, 6, 7]
    for k in [0, 1, 3, 8, 20]:
        print(f"k={k}: {rotate_list_right(sample, k)}")
15 0 Open
Lists & loops easy

Rotate List Left by k Positions in Python

Rotates a list left by k positions using slicing and modulo arithmetic to handle large k safely.

list rotation slicing
Python
def rotate_left(lst, k):
    if not lst:
        return []
    k = k % len(lst)
    return lst[k:] + lst[:k]

if __name__ == "__main__":
    my_list = [1, 2, 3, 4, 5]
    k = 2
    result = rotate_left(my_list, k)
    print(f"Original: {my_list}")
    print(f"After rotating left by {k}: {result}")
13 0 Open
Errors & debugging easy

How to Configure Python Logging with File Rotation

A complete demo that sets up a logger with a rotating file handler, writes several log entries, and shows the contents of the current log file.

logging file-handler rotating-file-handler
Python
import logging
from logging.handlers import RotatingFileHandler

logger = logging.getLogger("rotating_logger")
logger.setLevel(logging.DEBUG)

file_handler = RotatingFileHandler(
    "app.log",
    maxBytes=100,
    backupCount=3
)
file_handler.setFormatter(
    logging.Formatter("%(asctime)s - %(levelname)s - %(messa…
13 0 Open
Files & data easy

Rotate Log Files in Python by Size

This code rotates a log file when its size exceeds a threshold, keeping a specified number of backups.

log-rotation files os
Python
import os
import glob
from pathlib import Path

def rotate_log(log_path, max_size_bytes=1024, max_backups=3):
    log_file = Path(log_path)
    if log_file.stat().st_size <= max_size_bytes:
        print(f"Log size {log_file.stat().st_size} bytes <= threshold, no rotation")
        return

    for i in range(max_backu…
13 0 Open
Algorithms & data structures easy

How to Rotate an Array by k Steps in Python

This code rotates a list to the right by k positions using modulo arithmetic to handle k larger than the list length.

array rotation algorithms
Python
def rotate_array(nums, k):
    if not nums:
        return []
    n = len(nums)
    k = k % n
    return nums[-k:] + nums[:-k] if k else nums[:]

if __name__ == "__main__":
    arr = [1, 2, 3, 4, 5, 6]
    k = 2
    result = rotate_array(arr, k)
    print(f"Original: {arr}")
    print(f"Rotated by {k}: {result}")
13 0 Open
Automation & scripting easy

Restrict Secrets File Permissions with the chmod Script in Python

This script restricts a secrets file to 0600 permissions, rotates it to a dated backup, and creates a fresh protected file for secure automation workflows.

chmod permissions secrets
Python
import os
import sys
import stat
from pathlib import Path

def restrict_secrets_file(filepath: str) -> None:
    """Set restrictive permissions (0600) on a secrets file."""
    path = Path(filepath).expanduser()
    
    if not path.is_file():
        raise FileNotFoundError(f"Secrets file not found: {path}")
    
   …
13 0 Open
Observability & SRE easy

Rotate Log Files by Size in Python

A mock log rotation script that renames log files exceeding a size threshold, appending numbered backups.

log-rotation pathlib file-management
Python
import os
from pathlib import Path

def rotate_logs(directory: str, max_size: int = 100) -> None:
    """Rotate log files that exceed max_size bytes."""
    log_dir = Path(directory)
    for log_file in sorted(log_dir.glob("*.log"), key=lambda p: str(p)):
        if log_file.stat().st_size > max_size:
            for …
13 0 Open
Auth & security at scale easy

How to Mock a TLS Certificate Rotation Schedule in Python

Simulate a TLS certificate rotation schedule with a Python class that tracks last and next rotation dates and decides when to rotate.

tls certificates rotation
Python
import datetime
import random
import time


class CertRotator:
    def __init__(self, cert_name, rotation_days=30):
        self.cert_name = cert_name
        self.rotation_days = rotation_days
        self.last_rotated = datetime.date.today() - datetime.timedelta(days=random.randint(10, 25))
        self.next_rotatio…
16 0 Open

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How to use this library

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  2. Open a sample, read How it works, and copy the code block
  3. Run it in the IDE, tweak values, then take a related quiz or tutorial lesson

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.