Python

def fibonacci(n):
    if n <= 1:
        return n
    else:
        return fibonacci(n-1) + fibonacci(n-2)

def find_max(lst):
    if not lst:
        return None
    max_value = lst[0]
    for num in lst:
        if num > max_value:
            max_value = num
    return max_value

def reverse_string(s):
    return s[::-1]

def count_characters(s):
    count = {}
    for char in s:
        count[char] = count.get(char, 0) + 1
    return count

def common_elements(lst1, lst2):
    return list(set(lst1) & set(lst2))

import re

def is_valid_email(email):
    pattern = r"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$"
    return re.match(pattern, email) is not None

from datetime import datetime

def days_between_dates(date1, date2):
    d1 = datetime.strptime(date1, "%Y-%m-%d")
    d2 = datetime.strptime(date2, "%Y-%m-%d")
    return abs((d2 - d1).days)

def chunk_list(lst, size):
    return [lst[i:i + size] for i in range(0, len(lst), size)]

from urllib.parse import urlparse

def get_domain_name(url):
    return urlparse(url).netloc

def filter_even_numbers(lst):
    return [num for num in lst if num % 2 == 0]

import json

def read_json(file_path):
    with open(file_path, 'r') as file:
        return json.load(file)

from urllib.parse import urlparse, parse_qs

def extract_query_params(url):
    parsed_url = urlparse(url)
    return parse_qs(parsed_url.query)

from urllib.parse import urlparse

def extract_domain(url):
    return urlparse(url).netloc

import os

def get_file_extension(file_path):
    _, file_extension = os.path.splitext(file_path)
    return file_extension

import os

def list_files(directory):
    return [file for file in os.listdir(directory) if os.path.isfile(os.path.join(directory, file))]

import os

def join_path(directory, filename):
    return os.path.join(directory, filename)

import os

def file_exists(file_path):
    return os.path.isfile(file_path)

import os

def directory_exists(directory_path):
    return os.path.isdir(directory_path)

def find_median(dataset):
    sorted_list = sorted(dataset)
    length = len(sorted_list)
    if length % 2 == 0:
        return (sorted_list[length // 2 - 1] + sorted_list[length // 2]) / 2
    else:
        return sorted_list[length // 2]

def calculate_variance(data):
    mean = sum(data) / len(data)
    return sum((x - mean) ** 2 for x in data) / len(data)

def calculate_std_deviation(data):
    variance = calculate_variance(data)
    return variance ** 0.5

def calculate_correlation(x, y):
    mean_x = sum(x) / len(x)
    mean_y = sum(y) / len(y)
    numerator = sum((xi - mean_x) * (yi - mean_y) for xi, yi in zip(x, y))
    denominator = (sum((xi - mean_x) ** 2 for xi in x) * sum((yi - mean_y) ** 2 for yi in y)) ** 0.5
    return numerator / denominator if denominator else 0

import cv2
from PIL import Image, ImageDraw, ImageFont 
import numpy as np

def pil2cv(image):
    ''' PIL型 -> OpenCV型 '''
    new_image = np.array(image, dtype=np.uint8)
    if new_image.ndim == 2:  # モノクロ
        pass
    elif new_image.shape[2] == 3:  # カラー
        new_image = cv2.cvtColor(new_image, cv2.COLOR_RGB2BGR)
    elif new_image.shape[2] == 4:  # 透過
        new_image = cv2.cvtColor(new_image, cv2.COLOR_RGBA2BGRA)
    return new_image

import cv2
from PIL import Image, ImageDraw, ImageFont 
import numpy as np

def cv2pil(image):
    ''' OpenCV型 -> PIL型 '''
    new_image = image.copy()
    if new_image.ndim == 2:  # モノクロ
        pass
    elif new_image.shape[2] == 3:  # カラー
        new_image = cv2.cvtColor(new_image, cv2.COLOR_BGR2RGB)
    elif new_image.shape[2] == 4:  # 透過
        new_image = cv2.cvtColor(new_image, cv2.COLOR_BGRA2RGBA)
    new_image = Image.fromarray(new_image)
    return new_image

import os

def get_current_directory():
    return os.getcwd()

def create_directory(path):
    if not os.path.exists(path):
        os.makedirs(path)

def exists(path):
    return os.path.exists(path)

def list_directory_contents(directory):
    return os.listdir(directory)

def rename_or_move_file(current_path, new_path):
    os.rename(current_path, new_path)

import os

def list_directory_recursively(directory):
    paths = []
    for root, dirs, files in os.walk(directory):
        for name in files:
            paths.append(os.path.join(root, name))
        for name in dirs:
            paths.append(os.path.join(root, name))
    return paths

def get_file_size(file_path):
    return os.path.getsize(file_path)

def get_last_modification_time(path):
    return os.path.getmtime(path)

import os
import time

def change_file_metadata(path, access_time, modification_time):
    os.utime(path, (access_time, modification_time))

def find_executable_path(filename):
    for path in os.environ["PATH"].split(os.pathsep):
        full_path = os.path.join(path, filename)
        if os.path.isfile(full_path) and os.access(full_path, os.X_OK):
            return full_path
    return None

def remove_empty_directory(directory_path):
    try:
        os.rmdir(directory_path)
        return True
    except OSError:
        return False

import shutil

def copy_directory(source_directory, target_directory):
    shutil.copytree(source_directory, target_directory)

def change_permissions(path, mode):
    os.chmod(path, mode)

def change_owner(path, uid, gid):
    os.chown(path, uid, gid)

def create_symbolic_link(source, target):
    os.symlink(source, target)

def get_absolute_path(path):
    return os.path.abspath(path)

def get_directory_size(directory):
    total_size = 0
    for dirpath, dirnames, filenames in os.walk(directory):
        for f in filenames:
            fp = os.path.join(dirpath, f)
            if os.path.exists(fp):
                total_size += os.path.getsize(fp)
    return total_size