Python/Django后端使用PIL Image生成头像缩略图

import os
from django.views.generic import View
from myapp.models import User
from PIL import Image

def make_thumbnail(infile,thumbnail_dir):
 size = (156, 156)
 if not os.path.exists(thumbnail_dir):#判断缩略图存储目录是否存在then新建
 os.mkdir(thumbnail_dir)
 outfile = os.path.join( thumbnail_dir, os.path.basename(infile))
 try:
 im = Image.open(infile)#Key Point
 im.thumbnail(size)#Key Point
 im.save(outfile, "JPEG")#Key Point
 return True
 except IOError, err:
 print("cannot create thumbnail for", infile,err)
 return False

class Useravatar(View):
 def __init__(self):
 self.thumbnail_dir = os.path.join(STATIC_ROOT, 'avatar/thumbnails')
 self.dest_dir = os.path.join(STATIC_ROOT, 'avatar/origin_imgs')

 @method_decorator(login_required)
 def post(self, request):
 nt_id = request.session.get('nt_id', 'default')
 user = User.objects.get(pk=nt_id) if User.objects.filter(pk=nt_id).exists() else None
 avatarImg = request.FILES['avatar']
 if not os.path.exists(self.dest_dir):#判断原图存储目录是否存在then新建
  os.mkdir(self.dest_dir)
 dest = os.path.join(self.dest_dir, nt_id+"_avatar.jpg")
 with open(dest, "wb+") as destination:#先保存原图
  for chunk in avatarImg.chunks():
  destination.write(chunk)
 if make_thumb(dest,self.thumbnail_dir):#使用原图创建缩略图
  avartaPath = os.path.join(STATIC_URL, 'avatar/thumbnails', nt_id + "_avatar.jpg")
 else:
  avartaPath = os.path.join(STATIC_URL, 'avatar/origin_imgs', nt_id + "_avatar.jpg")

 User.objects.filter(nt_id=nt_id).update(avatar=avartaPath)
 return render(request, 'profile.html', {'user': user})