4

我正在提取 xml 文档中的所有文本。我想查找标签说描述，然后搜索所有子孙，可能会有更多元素，然后提取文本。

这是我的代码，但它无法在孙子标签中获取文本：

for element in root.find('description'):
    print 'parent: ', element.tag, '|', element.attrib
    try:
        data.write(element.text)
        for all_tags in element.findall('./'):
            print 'child: ', all_tags.tag, '|', all_tags.attrib
            if all_tags.text:
                data.write('\n')
                data.write(all_tags.text)
                if all_tags.tail:
                    data.write('\n')
                    data.write(all_tags.tail)
                    data.write('\n')
        data.write('\n')
    except TypeError:
        pass
    except UnicodeEncodeError:
        unicodestr = element.text.encode("utf-8")
        data.write(unicodestr)

    data.write('\n')

问题出在for all_tags循环中。

样本输入：

<description>
<p num="p-0003">
Protein kinases are involved in the signal transduction pathways linking growth factors, hormones and other cell regulation molecules to cell growth, survival and metabolism under both normal and pathological conditions. One such protein kinase, protein kinase B (also known as Akt), is a serine/threonine kinase that plays a central role in promoting the proliferation and survival of a wide range of cell types, thereby protecting cells from apoptosis (programmed cell death) (Khwaja,
<i>Nature</i>
33-34 (1990)). Three members of the Akt/PKB subfamily of second-messenger regulated serine/threonine protein kinases have been identified and are termed Akt1/PKBα, Akt2/PKBβ, and Akt3/PKBγ. A number of proteins involved in cell proliferation and survival have been described as substrates of Akt in cells. Two examples of such substrates include glycogen synthase kinase-3 (GSK3) and Forkhead transcription factors (FKs). See Brazil and Hemmings,
<i>Trends in Biochemical Sciences</i>
26, 675-664.
</p>
<p num="p-0004">
A number of protein kinases and phosphatases regulate the activity of Akt; For instance, activation of Akt is mediated by phosphatidylinositol 3-kinase (PI3-K), which initiates the binding of second messenger phospholipids to the pleckstrin homology (PH) binding domain of Akt. The binding anchors Akt to plasma membrane and results in phosphorylation and activation of the enzyme. Amplifications of the catalytic subunit of PI3-K, p110α, or mutations in the PI3-K regulatory subunit, p85α, lead to activation of Akt in several types of human cancer. (Vivanco and Sawyers,
<i>Nature Reviews in Cancer</i>
(2002) 2: 489-501.
</p>
<p num="p-0005">
The tumor suppressor, PTEN, is a critical negative regulator of Akt activation by PI3-K. Myers et al.
</p>
</description>

在此输入中，后面的文本<i> Nature </i> 被遗漏并替换为第一行中的文本。我相信这是因为all_tags.tail从父标签而不是子标签和孙标签中获取文本。

4

2 回答 2

6

element.findall('./')显式只查找标签的直接子代。查找所有后代的表达式是.//（双斜杠）。

针对给定示例的循环的简化版本，然后导致：

>>> for element in root:
...     print 'parent: ', element.tag, '|', element.attrib
...     print element.text
...     for all_tags in element.findall('.//'):
...         print 'child: ', all_tags.tag, '|', all_tags.attrib
...         if all_tags.text:
...             print all_tags.text, '|', all_tags.tail
... 
parent:  p | {'num': 'p-0003'}

Protein kinases are involved in the signal transduction pathways linking growth factors, hormones and other cell regulation molecules to cell growth, survival and metabolism under both normal and pathological conditions. One such protein kinase, protein kinase B (also known as Akt), is a serine/threonine kinase that plays a central role in promoting the proliferation and survival of a wide range of cell types, thereby protecting cells from apoptosis (programmed cell death) (Khwaja,

child:  i | {}
Nature | 
33-34 (1990)). Three members of the Akt/PKB subfamily of second-messenger regulated serine/threonine protein kinases have been identified and are termed Akt1/PKBα, Akt2/PKBβ, and Akt3/PKBγ. A number of proteins involved in cell proliferation and survival have been described as substrates of Akt in cells. Two examples of such substrates include glycogen synthase kinase-3 (GSK3) and Forkhead transcription factors (FKs). See Brazil and Hemmings,

child:  i | {}
Trends in Biochemical Sciences | 
26, 675-664.

parent:  p | {'num': 'p-0004'}

A number of protein kinases and phosphatases regulate the activity of Akt; For instance, activation of Akt is mediated by phosphatidylinositol 3-kinase (PI3-K), which initiates the binding of second messenger phospholipids to the pleckstrin homology (PH) binding domain of Akt. The binding anchors Akt to plasma membrane and results in phosphorylation and activation of the enzyme. Amplifications of the catalytic subunit of PI3-K, p110α, or mutations in the PI3-K regulatory subunit, p85α, lead to activation of Akt in several types of human cancer. (Vivanco and Sawyers,

child:  i | {}
Nature Reviews in Cancer | 
(2002) 2: 489-501.

parent:  p | {'num': 'p-0005'}

The tumor suppressor, PTEN, is a critical negative regulator of Akt activation by PI3-K. Myers et al.

或repr()用于显示字符串文字：

parent:  p | {'num': 'p-0003'}
'\nProtein kinases are involved in the signal transduction pathways linking growth factors, hormones and other cell regulation molecules to cell growth, survival and metabolism under both normal and pathological conditions. One such protein kinase, protein kinase B (also known as Akt), is a serine/threonine kinase that plays a central role in promoting the proliferation and survival of a wide range of cell types, thereby protecting cells from apoptosis (programmed cell death) (Khwaja,\n'
child:  i | {}
'Nature' | u'\n33-34 (1990)). Three members of the Akt/PKB subfamily of second-messenger regulated serine/threonine protein kinases have been identified and are termed Akt1/PKB\u03b1, Akt2/PKB\u03b2, and Akt3/PKB\u03b3. A number of proteins involved in cell proliferation and survival have been described as substrates of Akt in cells. Two examples of such substrates include glycogen synthase kinase-3 (GSK3) and Forkhead transcription factors (FKs). See Brazil and Hemmings,\n'
child:  i | {}
'Trends in Biochemical Sciences' | '\n26, 675-664.\n'
parent:  p | {'num': 'p-0004'}
u'\nA number of protein kinases and phosphatases regulate the activity of Akt; For instance, activation of Akt is mediated by phosphatidylinositol 3-kinase (PI3-K), which initiates the binding of second messenger phospholipids to the pleckstrin homology (PH) binding domain of Akt. The binding anchors Akt to plasma membrane and results in phosphorylation and activation of the enzyme. Amplifications of the catalytic subunit of PI3-K, p110\u03b1, or mutations in the PI3-K regulatory subunit, p85\u03b1, lead to activation of Akt in several types of human cancer. (Vivanco and Sawyers,\n'
child:  i | {}
'Nature Reviews in Cancer' | '\n(2002) 2: 489-501.\n'
parent:  p | {'num': 'p-0005'}
'\nThe tumor suppressor, PTEN, is a critical negative regulator of Akt activation by PI3-K. Myers et al.\n'
于 2013-05-23T16:48:52.000 回答
-1

您可能想使用 itertext()，但如果您想稍微提升您的游戏水平，您应该尝试xpath。在这些类型的情况下，它真的很闪耀。

这是一个例子 - 我给出的 xpath 基本上说：

在 XML 文档中的任意位置查找所有标记，然后返回它和所有子项的文本。

#!/usr/bin/python

from lxml import etree

tree = etree.fromstring(open('t.xml').read())

for el in tree.xpath('//description/descendant-or-self::*/text()'):
    print el
于 2013-05-23T17:04:04.007 回答