image_downloader.py

# pip install requests
import os
import requests

def get_extension(image_url: str) -> str | None:
    extensions: list[str] = ['.png', '.jpeg', '.jpg', '.gif']
    for ext in extensions:
        if ext in image_url:
            return ext
            break

def download_image(image_url: str, image_name: str, folder: str = None):
    if ext := get_extension(image_url):
        if folder:
            image_name = f'{folder}/{image_name}{ext}'
        else:
            image_name = f'{image_name}.{ext}'
    else:
        raise Exception('Image extension could not be located ...')        
    
    if os.path.isfile(image_name):
        raise Exception('File name already exists ...')

    # Downloading image
    try:
        image_content: bytes = requests.get(image_url).content
        with open(image_name, 'wb') as handler:
            handler.write(image_content)
            print(f'Downloaded {image_name} successfully!')
    except Exception as e:
        print(f'Error: {e}') 

if __name__ == '__main__':
    input_url: str = input('Enter a url: ')   
    input_name: str = input('What would you like to name it? ')
    print('Downloading ...')
    download_image(input_url, input_name, 'images')