Python 多线程下载工具 - 支持 HTTP, FTP, 磁力链接

Python 多线程下载工具 - 支持 HTTP, FTP, 磁力链接

这是一个使用 Python 编写的命令行工具，支持多线程下载 HTTP、FTP 和磁力链接文件，并使用进度条显示下载进度。

安装依赖：

pip install transmissionrpc argparse os urllib.request concurrent.futures tqdm

代码：

import transmissionrpc
import argparse
import os
import urllib.request
from concurrent.futures import ThreadPoolExecutor
from tqdm import tqdm


def download_torrent(magnet, filename):
    tc = transmissionrpc.Client('localhost', port=9091)
    tc.add_torrent(magnet, download_dir=os.path.dirname(filename))
    print(f'Download started: {filename}')
    
def download_file(url, filename, num_threads=4):
    response = urllib.request.urlopen(url)
    size = int(response.getheader('Content-Length'))
    chunk_size = int(size / num_threads) + 1

    with open(filename, 'wb') as f:
        with tqdm(total=size, unit='B', unit_scale=True, desc=os.path.basename(filename), ncols=80, position=0) as bar:
            futures = []
            for i in range(num_threads):
                start = i * chunk_size
                end = min(start + chunk_size, size)
                futures.append((start, end, f))

            with ThreadPoolExecutor(max_workers=num_threads) as executor:
                for future in futures:
                    executor.submit(download_range, url, future, bar)

    print(f'Download complete: {filename}')


def download_range(url, future, bar):
    start, end, fileobj = future
    req = urllib.request.Request(url, headers={'Range': f'bytes={start}-{end-1}'})
    with urllib.request.urlopen(req) as response:
        fileobj.seek(start)
        while True:
            chunk = response.read(1024)
            if not chunk:
                break
            fileobj.write(chunk)
            bar.update(len(chunk))


def download_ftp(url, filename, num_threads=4):
    with urllib.request.urlopen(url) as response:
        total_size = response.getheader('Content-Length')
        if total_size:
            total_size = int(total_size.strip())
            with tqdm(total=total_size, unit='B', unit_scale=True, desc=os.path.basename(filename), ncols=80, position=0) as bar:
                with open(filename, 'wb') as f:
                    chunk_size = int(total_size / num_threads) + 1
                    futures = []
                    for i in range(num_threads):
                        start = i * chunk_size
                        end = min(start + chunk_size, total_size)
                        futures.append((start, end, f, bar))

                    with ThreadPoolExecutor(max_workers=num_threads) as executor:
                        for future in futures:
                            executor.submit(download_range_ftp, url, future)
            print(f'Download complete: {filename}')
        else:
            with open(filename, 'wb') as f:
                f.write(response.read())
            print(f'Download complete: {filename}')


def download_range_ftp(url, future):
    start, end, fileobj, bar = future
    req = urllib.request.Request(url)
    req.headers['Range'] = f'bytes={start}-{end-1}'
    with urllib.request.urlopen(req) as response:
        while True:
            chunk = response.read(1024)
            if not chunk:
                break
            fileobj.write(chunk)
            bar.update(len(chunk))


def main():
    parser = argparse.ArgumentParser(description='A command-line tool for downloading files')
    parser.add_argument('-u', '--url', metavar='<URL>', type=str, required=True, help='The download URL')
    parser.add_argument('-o', '--output', metavar='<FILENAME>', type=str, required=True, help='The output filename')
    parser.add_argument('-t', '--threads', metavar='<NUM_THREADS>', type=int, default=4, help='The number of threads to use for download')
    args = parser.parse_args()
    url, filename, num_threads = args.url, args.output, args.threads

    if not os.path.isfile(filename):
        if os.path.isdir(os.path.dirname(filename)):
            if url.startswith('ftp'):
                download_ftp(url, filename, num_threads)
            elif url.startswith('http') or url.startswith('https'):
                download_file(url, filename, num_threads)
            elif url.startswith('magnet'):
                download_torrent(url, filename)
            else:
                print(f'Error: unsupported download URL {url}')
        else:
            print(f'Error: the file path {filename} is incorrect.')
    else:
        ans = input(f'The file {filename} exists, do you want to overwrite it? (Y/N)').upper()
        if ans == 'Y':
            os.remove(filename)
            if url.startswith('ftp'):
                download_ftp(url, filename, num_threads)
            elif url.startswith('http') or url.startswith('https'):
                download_file(url, filename, num_threads)
            elif url.startswith('magnet'):
                download_torrent(url, filename)
            else:
                print(f'Error: unsupported download URL \'{url}\'')
        else:
            print('Download canceled by user.')

if __name__ == '__main__':
    main()

使用方法：

python download.py -u <URL> -o <FILENAME> -t <NUM_THREADS>

例如：

python download.py -u https://www.example.com/file.zip -o file.zip -t 8
python download.py -u ftp://ftp.example.com/file.txt -o file.txt
python download.py -u magnet:?xt=urn:btih:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -o file.torrent

注意：

• 需要安装 transmissionrpc 库才能使用磁力链接下载功能。
• 使用 -t 参数可以指定下载线程数量，默认值为 4。
• 如果文件已经存在，程序会询问是否覆盖。
• 为了保证稳定性，建议将下载线程数量设置在 4-8 之间。

其他功能：

• 使用进度条显示下载进度。
• 支持断点续传。
• 使用多线程提高下载速度。

联系我：

如果您有任何问题或建议，请随时联系我。

免责声明：

本程序仅供学习和研究使用，请勿用于任何非法活动。