Python错误NoneType

Question

我有一个Python脚本，它使用BS4来获取网页的html。然后我在html中找到一个特定的头字段来提取文本。我这样做有以下几点：

r = br.open("http://example.com")
html = r.read()
r.close()
soup = BeautifulSoup(html)
# Get the contents of the html tag (h1) that displays results
searchResult = soup.find("h1").contents[0]
# Get only the number, remove all text
if not(searchResult == None):
    searchResultNum = int(re.match(r'\d+', searchResult).group())
else:
    searchResultNum = 696969

实际的HTML代码不会改变。它总是这样：

<div id="resultsCount">
    <h1 class="f12">606 Results matched</h1>
</div>

问题是，我的脚本可能运行4分钟（不同）并且崩溃：

Traceback (most recent call last):
  File "C:\Users\Me\Documents\Aptana Studio 3 Workspace\PythonScripts\PythonScripts\setupscript.py", line 109, in <module>
    searchResultNum = int(re.match(r'\d+', searchResult).group())
AttributeError: 'NoneType' object has no attribute 'group'

我以为我正在处理这个错误。我想我只是不明白。你能帮忙吗？

感谢。

Answer 1

如果searchResult未以数字re.match(r'\d+', searchResult)开头，则None和None没有组属性。另外if not(searchResult == None):有点不好，请使用if searchResult:

searchResultNum = 696969
if searchResult:
    m = re.match(r'\d+', searchResult)
    if m:
        searchResultNum = int(m.group())