如何使用 python Flask 创建下载 API 来下载文件

编程问答 2022-04-30

问题描述

我有一个 python 代码，它提供了来自 azure blob 存储的图像文件的下载 url。如果我们将此 url 复制粘贴到浏览器中，它只会下载文件。我必须创建一个下载 api，当调用它时将简单地下载文件。以下是我目前拥有的代码：

from urllib.request import urlopen
from flask import Flask,jsonify
import uuid
from flask_cors import CORS
from datetime import datetime
from azure.storage.blob import generate_blob_sas,AccountSasPermissions
import datetime
from datetime import timedelta


app = Flask(__name__)
CORS(app)

uid_secret_key = str(uuid.uuid4())

app.secret_key = uid_secret_key

# Make the Wsgi interface available at the top level so wfastcgi can get it.
wsgi_app = app.wsgi_app


@app.route('/download')
def download():
    account_name = "deeusblobstorage"
    container_name = "rperodct"
    blob_name = "face_1_7285.jpg"
    account_key = "hMlIRXCjAomfdrfied8Y5FPwTVnWEkEDuVsw//CQtkiOdcFD/y5wUcxH9Ou7Ni+DtDQFwe23YbZ3Qia9gw=="
    url = f"https://{account_name}.blob.core.windows.net/{container_name}/{blob_name}"
    sas_token = generate_blob_sas(
        account_name=account_name,account_key=account_key,container_name=container_name,blob_name=blob_name,permission=AccountSasPermissions(read=True),expiry=datetime.datetime.utcNow() + timedelta(hours=1)
    )

    url_with_sas = f"{url}?{sas_token}"
    print(url_with_sas)
    urlopen(url_with_sas)


@app.route('/')
def hello_world():
    return jsonify({'Status': 'ok','date': '05.25.21'}),200


if __name__ == '__main__':
    import os

    HOST = os.environ.get('SERVER_HOST','localhost')
    try:
        PORT = int(os.environ.get('SERVER_PORT','5555'))
    except ValueError:
        PORT = 5555
    app.run(HOST,PORT)

/download api 包含从变量名 url_with_sas 中的 azure 容器获取 blob 下载 url 的代码。现在我想以这样的方式制作这个 API，如果我们点击它，它应该自动从 url 下载文件。所以为此我想添加 urlopen(url_with_sas) 来打开网址。但似乎它不起作用。任何人都可以为此提供一些建议。谢谢

解决方法

正如评论中提到的，解决方案是通过 return redirect(url_with_sas) 所以整个函数看起来像这样：

@app.route('/download')
def download():
    account_name = "deeusblobstorage"
    container_name = "rperodct"
    blob_name = "face_1_7285.jpg"
    account_key = "hMlIRXCjAomfDRfied8Y5FPwTVnWEkEDuVsw//CQtkiOdcFD/y5wUcxH9Ou7Ni+DtDQFwe23YbZ3Qia9gw=="
    url = f"https://{account_name}.blob.core.windows.net/{container_name}/{blob_name}"
    sas_token = generate_blob_sas(
        account_name=account_name,account_key=account_key,container_name=container_name,blob_name=blob_name,permission=AccountSasPermissions(read=True),expiry=datetime.datetime.utcnow() + timedelta(hours=1)
    )

    url_with_sas = f"{url}?{sas_token}"
    return redirect(url_with_sas)
apiapidownloadflaskpython