完成函数时找不到临时文件

问题描述

我正在尝试创建一个临时文件，写入它，然后从我的flask应用程序下载它。但是，我在完成函数时收到FileNotFoundError。这是我的代码&收到的错误。提前谢谢。

    with tempfile.TemporaryFile (mode='w', newline="", dir=".", suffix='.csv') as csvfilenew:
        writer = csv.writer(csvfilenew, delimiter= ';')
        myClick()
        return send_file(str(csvfilenew.name), as_attachment=True, attachment_filename='cleanfile.csv')

FileNotFoundError: [Errno 2] No such file or directory: '/Desktop/bulk_final/10'

---

解决方案

TemporaryFile在请求Name属性时未返回有效的filedescriptor。您可以使用NamedTemporaryFile请求名称。

from flask import send_file
import tempfile
import csv

@app.route('/download')
def download():
    with tempfile.NamedTemporaryFile(mode='w', newline='', dir='.', suffix='.csv') as csvfilenew:
        writer = csv.writer(csvfilenew, delimiter= ';')
        writer.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam'])
        csvfilenew.flush()
        csvfilenew.seek(0)
        return send_file(csvfilenew.name,
            as_attachment=True,
            attachment_filename='cleanfile.csv'
        )

另一个适用于少量数据的简单解决方法如下：

from flask import send_file
import csv
import io

@app.route('/download')
def download():
    with io.StringIO() as doc:
        writer = csv.writer(doc, delimiter= ';')
        writer.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam'])
        doc.seek(0)
        return send_file(io.BytesIO(doc.read().encode('utf8')),
            as_attachment=True,
            attachment_filename='cleanfile.csv'
        )