试图理解 Django 源代码和缺少参数 TypeError 的原因

Question

A screenshot (portrait view) of my IDE and Traceback shows all the code pasteed here, 如果你有垂直显示器，可能更容易阅读。

上下文：尝试使用 S3BotoStorage 将图像从 URL 保存到托管在 EC2 上的 Django ImageField 以及 S3 上的文件。我很困惑，因为所有这些都表明 Django 仍然将其视为本地存储，而它应该是 S3。

似乎导致错误的相关行：

def get_filename(self, filename):
    return os.path.normpath(self.storage.get_valid_name(os.path.basename(filename)))

def get_valid_name(self, name):
    """
    Returns a filename, based on the provided filename, that's suitable for
    use in the target storage system.
    """
    return get_valid_filename(name)

类型错误异常：get_valid_name() missing 1 required positional argument: 'name'

在 get_valid_name 发生错误之前的最后一个局部变量 Tracback：

filename        'testimagefilename'
self        <django.db.models.fields.files.ImageField: image>

（只有这两个水平分隔线里面的东西是我的，其余的是Django 1.9的）

image.image.save('testimagefilename', File(temp), save=True)

当时来自 Traceback 的本地变量（不确定 image 上的 ValueError，我认为这是因为它尚未创建）：

File        <class 'django.core.files.base.File'>
image       Error in formatting: ValueError: The 'image' attribute has no file associated with it.
requests        <module 'requests' from '/usr/local/lib/python3.4/site-packages/requests/__init__.py'>
Image       <class 'mcmaster.models.Image'>
NamedTemporaryFile      <function NamedTemporaryFile at 0x7fb0e1bb0510>
temp        <tempfile._TemporaryFileWrapper object at 0x7fb0dd241ef0>

Django源码相关片段：

files.py

def save(self, name, content, save=True):
    name = self.field.generate_filename(self.instance, name)

    if func_supports_parameter(self.storage.save, 'max_length'):
        self.name = self.storage.save(name, content, max_length=self.field.max_length)
    else:
        warnings.warn(
            'Backwards compatibility for storage backends without '
            'support for the `max_length` argument in '
            'Storage.save() will be removed in Django 1.10.',
            RemovedInDjango110Warning, stacklevel=2
        )
        self.name = self.storage.save(name, content)

    setattr(self.instance, self.field.name, self.name)

    # Update the filesize cache
    self._size = content.size
    self._committed = True

    # Save the object because it has changed, unless save is False
    if save:
        self.instance.save()
save.alters_data = True

def get_directory_name(self):
    return os.path.normpath(force_text(datetime.datetime.now().strftime(force_str(self.upload_to))))

def get_filename(self, filename):
    return os.path.normpath(self.storage.get_valid_name(os.path.basename(filename)))

def generate_filename(self, instance, filename):
    # If upload_to is a callable, make sure that the path it returns is
    # passed through get_valid_name() of the underlying storage.
    if callable(self.upload_to):
        directory_name, filename = os.path.split(self.upload_to(instance, filename))
        filename = self.storage.get_valid_name(filename)
        return os.path.normpath(os.path.join(directory_name, filename))

    return os.path.join(self.get_directory_name(), self.get_filename(filename))

storage.py

def get_valid_name(self, name):
    """
    Returns a filename, based on the provided filename, that's suitable for
    use in the target storage system.
    """
    return get_valid_filename(name)

text.py

def get_valid_filename(s):
    """
    Returns the given string converted to a string that can be used for a clean
    filename. Specifically, leading and trailing spaces are removed; other
    spaces are converted to underscores; and anything that is not a unicode
    alphanumeric, dash, underscore, or dot, is removed.
    >>> get_valid_filename("john's portrait in 2004.jpg")
    'johns_portrait_in_2004.jpg'
    """
    s = force_text(s).strip().replace(' ', '_')
    return re.sub(r'(?u)[^-\w.]', '', s)
get_valid_filename = allow_lazy(get_valid_filename, six.text_type)

Answer 1

我猜你没有实例化存储 class。你如何设置 Django 以使用自定义存储？如果您在 models.py

中执行此操作

image = models.ImageField(storage=MyStorage)

它会完全按照您的描述失败。应该是

image = models.ImageField(storage=MyStorage())

试图理解 Django 源代码和缺少参数 TypeError 的原因

Trying to understand Django source code and cause of missing argument TypeError

python

django

boto

django-storage