fix invalid url scraping error

.gitignore

@@ -20,3 +20,6 @@ migrations/
 # deployed media and static files
 media/
 static/
+
+# log file
+log

books/views.py

@@ -468,13 +468,9 @@ def click_to_scrape(request):
             try:
                 scraped_book, raw_cover = scrape_douban_book(url)
             except TimeoutError:
-                return render(
-                    request,
-                    'common/error.html',
-                    {
-                        'msg': _("爬取数据失败😫"),
-                    }
-                )
+                return render(request, 'common/error.html', {'msg': _("爬取数据失败😫，请重试")})
+            except ValueError:
+                return render(request, 'common/error.html', {'msg': _("链接非法，爬取失败")})
             scraped_cover = {'cover': SimpleUploadedFile('temp.jpg', raw_cover)}
             form = BookForm(scraped_book, scraped_cover)
             if form.is_valid():
@@ -486,20 +482,7 @@ def click_to_scrape(request):
                     msg = _("ISBN与现有图书重复")
                 else:
                     msg = _("爬取数据失败😫")
-                return render(
-                    request,
-                    'common/error.html',
-                    {
-                        'msg': msg,
-                    }
-                )
-                return render(
-                    request,
-                    'common/error.html',
-                    {
-                        'msg': _("爬取数据失败😫"),
-                    }
-                )
+                return render(request, 'common/error.html', {'msg': msg})
         else:
             return HttpResponseBadRequest()
     else:

common/scraper.py

@@ -6,6 +6,7 @@ from boofilsic.settings import LUMINATI_USERNAME, LUMINATI_PASSWORD, DEBUG
 
 RE_NUMBERS = re.compile(r"\d+\d*")
 RE_WHITESPACES = re.compile(r"\s+")
+RE_DOUBAN_BOOK_URL = re.compile(r"https://book.douban.com/subject/\d+/")
 
 DEFAULT_REQUEST_HEADERS = {
     'Host': 'book.douban.com',
@@ -28,6 +29,9 @@ PORT = 22225
 
 
 def scrape_douban_book(url):
+    if RE_DOUBAN_BOOK_URL.match(url) is None:
+        raise ValueError("not valid douban book url")
+
     session_id = random.random()
     proxy_url = ('http://%s-country-cn-session-%s:%s@zproxy.lum-superproxy.io:%d' %
         (LUMINATI_USERNAME, session_id, LUMINATI_PASSWORD, PORT))
@@ -42,7 +46,10 @@ def scrape_douban_book(url):
     
     content = html.fromstring(r.content.decode('utf-8'))
 
+    try:
         title = content.xpath("/html/body/div[3]/h1/span/text()")[0].strip()
+    except IndexError:
+        raise ValueError("given url contains no book info")
 
     subtitle_elem = content.xpath("//div[@id='info']//span[text()='副标题:']/following::text()")
     subtitle = subtitle_elem[0].strip() if subtitle_elem else None