如何利用Python对接又拍云接口，实现视频裁剪与合并功能

import requests
import hashlib
import time

# 替换为你的API密钥和存储空间名
operator = 'your_operator'
password = 'your_password'
bucket = 'your_bucket_name'

# 获取当前时间戳
timestamp = int(time.time())

# 构造签名字符串
sign_string = '{0}&{1}&{2}'.format(operator, password, timestamp)

# 计算签名
md5 = hashlib.md5()
md5.update(sign_string.encode('utf-8'))
signature = md5.hexdigest()

# 发起视频裁剪任务
def crop_video(filename, start, end):
    # 请求URL
    url = 'http://v0.api.upyun.com/{0}/transcoding/'.format(bucket)

    # 构造请求参数
    params = {
        'source': filename,
        'start': start,
        'end': end,
        'notify_url': 'http://your_notify_url',
        'signature': signature,
        'timestamp': timestamp
    }

    # 发起POST请求
    response = requests.post(url, data=params)

    # 获取响应结果
    result = response.json()
    return result

# 发起视频合并任务
def merge_videos(filenames, save_as):
    # 请求URL
    url = 'http://v0.api.upyun.com/{0}/merge/'.format(bucket)

    # 构造请求参数
    params = {
        'files': ';'.join(filenames),
        'save_as': save_as,
        'signature': signature,
        'timestamp': timestamp
    }

    # 发起POST请求
    response = requests.post(url, data=params)

    # 获取响应结果
    result = response.json()
    return result

# 调用视频裁剪接口示例
crop_result = crop_video('origin_video.mp4', 10, 20)
print(crop_result)

# 调用视频合并接口示例
merge_result = merge_videos(['video1.mp4', 'video2.mp4', 'video3.mp4'], 'merged_video.mp4')
print(merge_result)