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如果我要在内存中创建一个类似文件的 csv 对象，如下所示：

output_stream = io.StringIO()
sheet = pyexcel.get_sheet(records=data)
sheet.save_to_memory(file_type='csv', stream=output_stream)

如何使用 Django 将 output_stream 中的对象之类的文件保存到我的 default_storage 后端的文件中？

class Example(models.Model):
    model_file = models.FileField(upload_to='', max_length=255, blank=True, null=True)

我试过类似的东西：

self.model_file.save(filename, ContentFile(output_stream.read()))

但我收到以下错误：

"TypeError: ('data must be bytes, received', <class 'str'>)"

pyexcel 仅支持用于 csv 类型文件的 io.StringIO 流。

追溯：

...
  File "C:\Users\Cole\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\core\files\storage.py", line 49, in save
    return self._save(name, content)
  File "C:\Users\Cole\AppData\Local\Programs\Python\Python36-32\lib\site-packages\storages\backends\gcloud.py", line 167, in _save
    content_type=file.mime_type)
  File "C:\Users\Cole\AppData\Local\Programs\Python\Python36-32\lib\site-packages\google\cloud\storage\blob.py", line 1034, in upload_from_file
    size, num_retries, predefined_acl)
  File "C:\Users\Cole\AppData\Local\Programs\Python\Python36-32\lib\site-packages\google\cloud\storage\blob.py", line 947, in _do_upload
    size, num_retries, predefined_acl)
  File "C:\Users\Cole\AppData\Local\Programs\Python\Python36-32\lib\site-packages\google\cloud\storage\blob.py", line 759, in _do_multipart_upload
    transport, data, object_metadata, content_type)
  File "C:\Users\Cole\AppData\Local\Programs\Python\Python36-32\lib\site-packages\google\resumable_media\requests\upload.py", line 94, in transmit
    data, metadata, content_type)
  File "C:\Users\Cole\AppData\Local\Programs\Python\Python36-32\lib\site-packages\google\resumable_media\_upload.py", line 270, in _prepare_request
    raise TypeError(u'`data` must be bytes, received', type(data))
TypeError: ('`data` must be bytes, received', <class 'str'>)
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1 回答 1

3

您可以像这样从 a 读取内容StringIO并转换为 utf8 编码字节。

self.model_file.save(filename, ContentFile(output_stream.getvalue().encode()))

getvalue()类似于read()，但无论当前流位置如何，您将始终获得 StringIO 的全部内容。read()你可能不得不使用seek(0).

于 2018-07-21T21:28:05.143 回答