validators.py 文件源码

def __call__(self, value):
        """
        Check the extension, content type and file size.
        """

        # Check the extension
        ext = splitext(value.name)[1][1:].lower()
        if self.allowed_extensions and ext not in self.allowed_extensions:
            message = self.extension_message % {
                'extension': ext,
                'allowed_extensions': ', '.join(self.allowed_extensions)
            }

            raise ValidationError(message)

        # Check the content type
        mimetype = mimetypes.guess_type(value.name)[0]
        if self.allowed_mimetypes and mimetype not in self.allowed_mimetypes:
            message = self.mime_message % {
                'mimetype': mimetype,
                'allowed_mimetypes': ', '.join(self.allowed_mimetypes)
            }

            raise ValidationError(message)

        # Check the file size
        filesize = len(value)
        if self.max_size and filesize > self.max_size:
            message = self.max_size_message % {
                'size': filesizeformat(filesize),
                'allowed_size': filesizeformat(self.max_size)
            }

            raise ValidationError(message)

        elif filesize < self.min_size:
            message = self.min_size_message % {
                'size': filesizeformat(filesize),
                'allowed_size': filesizeformat(self.min_size)
            }

            raise ValidationError(message)