Question

我试图抓住这个网站，但是当我尝试打印出桌面的内容时，我一直收到错误。

soup = BeautifulSoup(urllib2.urlopen('http://clinicaltrials.gov/show/NCT01718158
').read())

print soup('table')[6].prettify()


for row in soup('table')[6].findAll('tr'):
    tds = row('td')
    print tds[0].string,tds[1].string

IndexError                                Traceback (most recent call last)
<ipython-input-70-da84e74ab3b1> in <module>()
  1 for row in soup('table')[6].findAll('tr'):
  2     tds = row('td')
  3     print tds[0].string,tds[1].string
  4 

IndexError: list index out of range

Answer 1

该表有一个标题行，包含 <th> 标题元素而不是<td>个单元格。您的代码假定每行中始终存在<td>个元素，而第一行的元素将失败。

您可以跳过没有<td>元素的行：

for row in soup('table')[6].findAll('tr'):
    tds = row('td')
    if len(tds) < 2:
        continue
    print tds[0].string, tds[1].string

此时你得到输出：

>>> for row in soup('table')[6].findAll('tr'):
...     tds = row('td')
...     if len(tds) < 2:
...         continue
...     print tds[0].string, tds[1].string
... 
Responsible Party: Bristol-Myers Squibb
ClinicalTrials.gov Identifier: None
Other Study ID Numbers: AI452-021, 2011‐005409‐65
Study First Received: October 29, 2012
Last Updated: November 7, 2014
Health Authority: None

最后一行包含散布着<br/>元素的文字;您可以使用element.strings生成器来提取所有字符串，并可能将它们连接到换行符中;我首先剥离每个字符串：

>>> for row in soup('table')[6].findAll('tr'):
...     tds = row('td')
...     if len(tds) < 2:
...         continue
...     print tds[0].string, '\n'.join(filter(unicode.strip, tds[1].strings))
... 
Responsible Party: Bristol-Myers Squibb
ClinicalTrials.gov Identifier: NCT01718158
History of Changes
Other Study ID Numbers: AI452-021, 2011‐005409‐65
Study First Received: October 29, 2012
Last Updated: November 7, 2014
Health Authority: United States: Institutional Review Board
United States: Food and Drug Administration
Argentina: Administracion Nacional de Medicamentos, Alimentos y Tecnologia Medica
France: Afssaps - Agence française de sécurité sanitaire des produits de santé (Saint-Denis)
Germany: Federal Institute for Drugs and Medical Devices
Germany: Ministry of Health
Israel: Israeli Health Ministry Pharmaceutical Administration
Israel: Ministry of Health
Italy: Ministry of Health
Italy: National Bioethics Committee
Italy: National Institute of Health
Italy: National Monitoring Centre for Clinical Trials - Ministry of Health
Italy: The Italian Medicines Agency
Japan: Pharmaceuticals and Medical Devices Agency
Japan: Ministry of Health, Labor and Welfare
Korea: Food and Drug Administration
Poland: National Institute of Medicines
Poland: Ministry of Health
Poland: Ministry of Science and Higher Education
Poland: Office for Registration of Medicinal Products, Medical Devices and Biocidal Products
Russia: FSI Scientific Center of Expertise of Medical Application
Russia: Ethics Committee
Russia: Ministry of Health of the Russian Federation
Spain: Spanish Agency of Medicines
Taiwan: Department of Health
Taiwan: National Bureau of Controlled Drugs
United Kingdom: Medicines and Healthcare Products Regulatory Agency

Python：html表内容

1 个答案: