Python 为什么来自BeautifulSoup的解析会抛出错误

我有这个HTML源代码：-

http://pastebin.com/itMYaimq

。我正在运行下面的BeautifulSoup命令来解析HTML

def check_img(self, feed):
        return 1 if feed.find_all('img', attrs={'data-blzsrc': True, 'src': lambda x: 'data' not in x}) else 0

这里的

提要

是HTML源

在执行时，这将抛出

[2015-01-08 10:19:16,415: WARNING/Worker-2] Traceback (most recent call last):
[2015-01-08 10:19:16,415: WARNING/Worker-2] File "/Users/rokumar/SiteAnalysisGit/Src/hct/hct/data_processors/rule_processor.py", line 58, in do_akamai_analysis
[2015-01-08 10:19:16,416: WARNING/Worker-2] resp, self.analysis.url, self.analysis.id)
[2015-01-08 10:19:16,416: WARNING/Worker-2] File "/Users/rokumar/SiteAnalysisGit/Src/hct/hct/rules.py", line 794, in akamai_rule_analysis
[2015-01-08 10:19:16,416: WARNING/Worker-2] result[RULES.FEO_CHECKS] = check_feo_optimizations(analysis_id, url)
[2015-01-08 10:19:16,417: WARNING/Worker-2] File "/Users/rokumar/SiteAnalysisGit/Src/hct/hct/rules.py", line 1320, in check_feo_optimizations
[2015-01-08 10:19:16,417: WARNING/Worker-2] return FEO_processor.FEOProcessor().process_feo_debug_output(analysis_id, url)
[2015-01-08 10:19:16,417: WARNING/Worker-2] File "/Users/rokumar/SiteAnalysisGit/Src/hct/hct/data_processors/FEO_processor.py", line 38, in process_feo_debug_output
[2015-01-08 10:19:16,417: WARNING/Worker-2] self.result[name] = (False, True)[getattr(self,func)(feed)]
[2015-01-08 10:19:16,418: WARNING/Worker-2] File "/Users/rokumar/SiteAnalysisGit/Src/hct/hct/data_processors/FEO_processor.py", line 64, in check_img
[2015-01-08 10:19:16,418: WARNING/Worker-2] return 1 if feed.find_all('img', attrs={'data-blzsrc': True, 'src': lambda x: 'data' not in x}) else 0
[2015-01-08 10:19:16,418: WARNING/Worker-2] File "/Library/Python/2.7/site-packages/bs4/element.py", line 1180, in find_all
[2015-01-08 10:19:16,419: WARNING/Worker-2] return self._find_all(name, attrs, text, limit, generator, **kwargs)
[2015-01-08 10:19:16,419: WARNING/Worker-2] File "/Library/Python/2.7/site-packages/bs4/element.py", line 505, in _find_all
[2015-01-08 10:19:16,419: WARNING/Worker-2] found = strainer.search(i)
[2015-01-08 10:19:16,420: WARNING/Worker-2] File "/Library/Python/2.7/site-packages/bs4/element.py", line 1540, in search
[2015-01-08 10:19:16,420: WARNING/Worker-2] found = self.search_tag(markup)
[2015-01-08 10:19:16,420: WARNING/Worker-2] File "/Library/Python/2.7/site-packages/bs4/element.py", line 1512, in search_tag
[2015-01-08 10:19:16,421: WARNING/Worker-2] if not self._matches(attr_value, match_against):
[2015-01-08 10:19:16,421: WARNING/Worker-2] File "/Library/Python/2.7/site-packages/bs4/element.py", line 1578, in _matches
[2015-01-08 10:19:16,421: WARNING/Worker-2] return match_against(markup)
[2015-01-08 10:19:16,421: WARNING/Worker-2] File "/Users/rokumar/SiteAnalysisGit/Src/hct/hct/data_processors/FEO_processor.py", line 64, in <lambda>
[2015-01-08 10:19:16,422: WARNING/Worker-2] return 1 if feed.find_all('img', attrs={'data-blzsrc': True, 'src': lambda x: 'data' not in x}) else 0
[2015-01-08 10:19:16,422: WARNING/Worker-2] TypeError: argument of type 'NoneType' is not itterable

[2015-01-08 10:19:16415:警告/Worker-2]回溯（最近一次呼叫最后一次）：
[2015-01-08 10:19:16415:WARNING/Worker-2]文件“/Users/rokumar/sitelanalysisgit/Src/hct/hct/data\u processors/rule\u processor.py”，第58行，在do\u akamai\u analysis中
[2015-01-08 10:19:16416:WARNING/Worker-2]resp，self.analysis.url，self.analysis.id）
[2015-01-08 10:19:16416:WARNING/Worker-2]文件“/Users/rokumar/sitelanalysisgit/Src/hct/hct/rules.py”，第794行，akamai规则分析
[2015-01-08 10:19:16416:WARNING/Worker-2]结果[RULES.FEO_CHECKS]=检查优化（分析id、url）
[2015-01-08 10:19:16417:WARNING/Worker-2]文件“/Users/rokumar/sitelanalysisgit/Src/hct/hct/rules.py”，第1320行，检查优化
[2015-01-08 10:19:16417:WARNING/Worker-2]返回FEO_处理器。FEOProcessor（）。处理调试输出（分析id，url）
[2015-01-08 10:19:16417:WARNING/Worker-2]文件“/Users/rokumar/sitelanalysisgit/Src/hct/hct/data\u processors/FEO\u processor.py”，第38行，进程中调试输出
[2015-01-08 10:19:16417:WARNING/Worker-2]self.result[name]=（False，True）[getattr（self，func）（feed）]
[2015-01-08 10:19:16418:WARNING/Worker-2]文件“/Users/rokumar/sitelanalysisgit/Src/hct/hct/data\u processors/FEO\u processor.py”，第64行，检查img
[2015-01-08 10:19:16418:警告/Worker-2]如果feed返回1。find_all（'img'，attrs={'data-blzsrc'：True，'src'：lambda x:'data'不在x}）否则0
[2015-01-08 10:19:16418:WARNING/Worker-2]文件“/Library/Python/2.7/site packages/bs4/element.py”，第1180行，全部查找
[2015-01-08 10:19:16419:WARNING/Worker-2]返回self.\u find_all（名称、属性、文本、限制、生成器，**kwargs）
[2015-01-08 10:19:16419:WARNING/Worker-2]文件“/Library/Python/2.7/site packages/bs4/element.py”，第505行，全部查找
[2015-01-08 10:19:16419:警告/工人-2]发现=过滤器。搜索（i）
[2015-01-08 10:19:16420:WARNING/Worker-2]文件“/Library/Python/2.7/site packages/bs4/element.py”，第1540行，搜索中
[2015-01-08 10:19:16420:WARNING/Worker-2]found=self.search_标记（标记）
[2015-01-08 10:19:16420:WARNING/Worker-2]文件“/Library/Python/2.7/site packages/bs4/element.py”，第1512行，在搜索标签中
[2015-01-08 10:19:16421:警告/工人-2]如果不匹配自身（属性值，匹配）：
[2015-01-08 10:19:16421:WARNING/Worker-2]文件“/Library/Python/2.7/site packages/bs4/element.py”，第1578行，在
[2015-01-08 10:19:16421:WARNING/Worker-2]返回匹配（标记）
[2015-01-08 10:19:16421:WARNING/Worker-2]文件“/Users/rokumar/sitelanalysisgit/Src/hct/hct/data_processors/FEO_processor.py”，第64行
[2015-01-08 10:19:16422:警告/Worker-2]如果feed返回1。find_all（'img'，attrs={'data-blzsrc'：True，'src'：lambda x:'data'不在x}）否则0
[2015-01-08 10:19:16422:警告/Worker-2]类型错误：类型为“NoneType”的参数不可写入

---

我已经打印了

提要

，以查看其值。它打印了HTML源代码，因此它不是

None

。那么，为什么我会得到这个错误，因为'NoneType'类型的

参数不可测试

您的

src

lambda正在测试

None

：

>>> x = None
>>> 'data' not in x
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: argument of type 'NoneType' is not iterable

简单测试一下：

lambda x: x and 'data' not in x

你的测试可以简化；无需查找所有匹配项，只需查找第一个：

blzsrc_image = feed.find('img', attrs={'data-blzsrc': True, 'src': lambda x: 'data' not in x})
return 1 if blzsrc_image else 0

如果布尔值可用（而不是

1

或

0

），则可以使用：

blzsrc_image = feed.find('img', attrs={'data-blzsrc': True, 'src': lambda x: 'data' not in x})
return blzsrc_image is not None

---

如果

feed

将是

None

，则会得到

AttributeError:“NoneType”对象没有属性“find\u all”

。你确定

x

中有什么吗

'data'不在None中

将给出

类型为'NoneType'的参数不可编辑

。x应该具有

img

标记的

src

属性。您可以在这里看到HTML您手动键入此回溯了吗？您在

iterable

中有拼写错误…第1885行中的

img

标记没有

src

属性。而这只是许多例子中的第一个。

blzsrc_image = feed.find('img', attrs={'data-blzsrc': True, 'src': lambda x: 'data' not in x})
return blzsrc_image is not None