要上传文件到Autodesk Construction Cloud并获取最后修改时间，你可以使用Autodesk Forge API和Python编程语言。

首先，确保你已经创建了Autodesk Forge开发者帐户，并拥有访问Autodesk Construction Cloud的权限。然后，按照以下步骤进行操作：

1. 安装所需的Python库。在命令行中运行以下命令：

pip install requests

2. 引入所需的库和模块：

import requests
import json
import datetime

3. 设置Autodesk Forge API的访问令牌：

access_token = "YOUR_ACCESS_TOKEN"

你需要将"YOUR_ACCESS_TOKEN"替换为你的实际访问令牌。

4. 创建一个函数来上传文件并获取最后修改时间：

def upload_file_and_get_last_modified_time(file_path, folder_id):
    # 将文件上传到Autodesk Construction Cloud
    upload_url = "https://developer.api.autodesk.com/data/v1/projects/PROJECT_ID/folders/" + folder_id + "/items"
    headers = {
        "Authorization": "Bearer " + access_token,
        "Content-Type": "application/vnd.api+json"
    }
    data = {
        "jsonapi": {
            "version": "1.0"
        },
        "data": {
            "type": "items",
            "attributes": {
                "displayName": file_path.split("/")[-1],
                "extension": {
                    "type": "items:autodesk.bim360:File",
                    "version": "1.0"
                }
            },
            "relationships": {
                "tip": {
                    "data": {
                        "type": "versions",
                        "id": "1"
                    }
                },
                "parent": {
                    "data": {
                        "type": "folders",
                        "id": folder_id
                    }
                }
            }
        }
    }
    response = requests.post(upload_url, headers=headers, data=json.dumps(data))
    response_json = response.json()
    version_id = response_json["data"]["relationships"]["tip"]["data"]["id"]

    # 获取文件的最后修改时间
    version_url = "https://developer.api.autodesk.com/data/v1/projects/PROJECT_ID/versions/" + version_id
    response = requests.get(version_url, headers=headers)
    response_json = response.json()
    last_modified_time = response_json["data"]["attributes"]["lastModifiedTime"]
    last_modified_time = datetime.datetime.fromisoformat(last_modified_time)

    return last_modified_time

请将"PROJECT_ID"替换为你的实际项目ID。

5. 调用函数并传入文件路径和目标文件夹ID：

file_path = "path/to/your/file.txt"
folder_id = "your_folder_id"
last_modified_time = upload_file_and_get_last_modified_time(file_path, folder_id)
print("Last modified time:", last_modified_time)

请将"your_folder_id"替换为你的实际文件夹ID。

这样，你就可以上传文件并获取其最后修改时间了。确保在调用API时提供正确的访问令牌和项目ID，以及文件路径和目标文件夹ID。