Question

我正在网站（Django 2.1）上嵌入视频，我需要使用外部脚本填充数据库。我有两个表，其中一个是父表（视频）和子表（缩略图），其中imageField是。我需要从URL下载缩略图，并以编程方式将图像插入ImageField。我正在为这个问题奋斗2天。我已经在这里阅读了一些关于stackoverflow的建议，但是对我没有任何帮助，我在这里放弃了。有人可以帮我吗？

这是我模型的一部分：

#my models.py

class Video(models.Model):
    title = models.CharField(max_length=255)
    slug = models.SlugField(max_length=255, unique = True)
    video_url = models.URLField(max_length=255, unique = True)

class Thumbnail(models.Model): 
    name = models.CharField(max_length=50)   
    thumb = models.ImageField(upload_to='thumb/', null=True, blank=True)
    thumb_resolution = models.CharField(max_length=50, null=True, blank=True)
    videos = models.ForeignKey(Video, on_delete=models.CASCADE, related_name='thumbnails')

这里是我的下载代码的简化版本，我尝试了几种不同的方式，但是大多数尝试均以没有错误的结尾结束，但是MEDIA文件夹中没有文件。但是我的“视频”和“缩略图”之间的OneToMany关系已成功创建。

import requests
from io import BytesIO
from PIL import Image
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "video.settings")
import django
django.setup()
from django.core.files import File
from django.core.files.base import ContentFile
from mainSite.models import Video, Thumbnail

def download(url):
    try:
        r = requests.get(url) 
        if not r.status_code == 200:
            raise Exception('file request failed with status code: ' + str(r.status_code))
        return (r.content)
    except Exception as ex:
        print (ex)
        return ('error')

VIDEO_URL = "https://videowebsite.com/video/43332"
VIDEO_THUMBS = ["https://videowebsite.com/thumb/1.jpg","https://videowebsite.com/thumb/2.jpg"]

# title, slug , video_url exist in my code
add_video = Video(title=title,slug=slug,video_url=video_url)
add_video.save()

for image in VIDEO_THUMBS:
    get_file = download(image)
    file_name = image.split('/')[-1]
    if get_file != 'error' and len(get_file) > 0:
    # I tried several different ways here but none of them work.


        f = BytesIO(get_file)
        Thumbnail(name=file_name, thumb=File(f), videos = add_video).save()
        #No error but image does not exist on server in MEDIA folder
        #--------------------------------------------
        with Image.open(get_file) as img:
            Thumbnail(name=file_name, thumb=ContentFile(img), videos = add_video).save()
            # ValueError: embedded null byte
        #--------------------------------------------
        Thumbnail(name=file_name, thumb=File(get_file), videos = add_video).save()
        # No error but image does not exist on server
        #--------------------------------------------
        with Image.open(get_file) as img:
            Thumbnail(name=file_name, thumb=File(img), videos = add_video).save()
        # No error but image does not exist on server
        #--------------------------------------------
        f = BytesIO(get_file)
        with Image.open(f) as img:
            Thumbnail(name=file_name, thumb=File(img), videos = add_video).save()
        #Again no error but images does not exist
    else:
        print('error')

我真的在这里迷路了，有人可以告诉我我在做什么错吗？在大多数情况下，没有错误，父表和子表之间的关系已成功创建，但是图像未上载到MEDIA / thumb文件夹中。预先非常感谢。

Answer 1

解决方案：

from io import BytesIO

from django.core.files.base import ContentFile
from PIL import Image


for image in VIDEO_THUMBS:
    get_file = download(image)
    file_name = image.split('/')[-1]

    # please read https://pillow.readthedocs.io/en/3.1.x/handbook/image-file-formats.html
    # for available formats.
    extension = 'jpeg'

    f = BytesIO(get_file)
    out = BytesIO()

    image = Image.open(f)
    image.save(out, extension)

    t = Thumbnail(<all fields except thumb>)
    t.thumb.save(file_name, ContentFile(out.getvalue()), save=False)
    t.save()

将文件保存到内存[变量out]
使用Django的ContentFile类初始化内存中的文件内容

编辑：您不需要StringIO，BytesIO将完成这项工作。

Answer 2

到目前为止，我已经能够克服它，但是我必须将映像保存到磁盘，然后再次读取文件，这可以根据需要工作。

for image in VIDEO_THUMBS:
    get_file = download(image)
    file_name = image.split('/')[-1]

    if get_file != 'error' and len(get_file) > 0:  
        with open('temp/temp.jpg', 'wb') as f:
            f.write(get_file)                
        with open('temp/temp.jpg', 'rb') as f:
            fi = f.read()
        t = Thumbnail(name=file_name, videos = add_video)
        t.thumb.save(file_name, ContentFile(fi), save=False)
        t.save()
    else:
        print('error')

Django-使用外部脚本从url下载图像并将其插入imageField

2 个答案: