根據路徑編輯XML文件文本

Question

我有一個XML文件（例如jerry.xml），其中包含一些數據，如下所示。

<data>
<country name="Peru">
    <rank updated="yes">2</rank>
    <language>english</language>
    <currency>1.21$/kg</currency> 
    <gdppc month="06">141100</gdppc>
    <gdpnp month="10">2.304e+0150</gdpnp>
    <neighbor name="Austria" direction="E"/>
    <neighbor name="Switzerland" direction="W"/>
</country>
<country name="Singapore">
    <rank updated="yes">5</rank>
    <language>english</language>
    <currency>4.1$/kg</currency> 
    <gdppc month="05">59900</gdppc>
    <gdpnp month="08">1.9e-015</gdpnp>
    <neighbor name="Malaysia" direction="N"/>
</country>

我使用下面的代碼從上面的xml中提取了一些選定文本的完整路徑。 原因在這篇文章中給出。

def extractNumbers(path, node):
    nums = []

    if 'month' in node.attrib:
        if node.attrib['month'] in ['05', '06']:
            return nums

    path += '/' + node.tag
    if 'name' in node.keys():
        path += '=' + node.attrib['name']

    elif 'year' in node.keys():
        path += ' ' + 'month' + '=' + node.attrib['month']
    try:
        num = float(node.text)
        nums.append( (path, num) )
    except (ValueError, TypeError):
        pass
    for e in list(node):
        nums.extend( extractNumbers(path, e) )
    return nums

tree = ET.parse('jerry.xml')
nums = extractNumbers('', tree.getroot())
print len(nums)
print nums

這給了我需要改變的元素的位置，如下面csv的colomn 1所示（例如hrong.csv）。

Path                                                      Text1       Text2       Text3       Text4       Text5 
'/data/country name=singapore/gdpnp month=08';            5.2e-015;   2e-05;      8e-06;      9e-04;      0.4e-05;   
'/data/country name=peru/gdppc month=06';                 0.04;       0.02;       0.15;       3.24;       0.98;                                                 

我想根據第1列中元素的位置，用上面hrong.csv的第2列中的元素替換原始XML文件（jerry.xml）元素的文本。

我是python的新手，並意識到我可能沒有使用最好的方法。 我很感激任何有關方向的幫助。 我基本上只需解析一些xml文件的選定文本節點，修改所選文本節點並保存每個文件。

謝謝

Answer 1

您應該能夠使用模塊的XPath功能來執行此操作：

import xml.etree.ElementTree as ET
tree = ET.parse('jerry.xml')
root = tree.getroot()
for data in root.findall(".//country[@name='singapore']/gdpnp[@month='08']"):
    data.text = csv_value

tree.write("filename.xml")

因此，您需要重寫csv中的路徑以匹配為模塊定義的XPath規則（請參閱支持的XPath規則 ）。

Answer 2

首先， 記錄如何修改XML 。 現在，這是我自己的例子：

import xml.etree.ElementTree as ET

s = """
<root>
    <parent attribute="value">
        <child_1 other_attr="other_value">child text</child_1>
        <child_2 yet_another_attr="another_value">more child text</child_2>
    </parent>
</root>
"""

root = ET.fromstring(s)

for parent in root.getchildren():
    parent.attrib['attribute'] = 'new value'
    for child in parent.getchildren():
        child.attrib['new_attrib'] = 'new attribute for {}'.format(child.tag)
        child.text += ', appended text!'

>>> ET.dump(root)
<root>
    <parent attribute="new value">
        <child_1 new_attrib="new attribute for child_1" other_attr="other_value">child text, appended text!</child_1>
        <child_2 new_attrib="new attribute for child_2" yet_another_attr="another_value">more child text, appended text!</child_2>
    </parent>
</root>

你也可以用Xpath做到這一點。

>>> root.find('parent/child_1[@other_attr]').attrib['other_attr'] = 'found it!'
>>> ET.dump(root)
<root>
    <parent attribute="new value">
        <child_1 new_attrib="new attribute for child_1" other_attr="found it!">child text, appended text!</child_1>
        <child_2 new_attrib="new attribute for child_2" yet_another_attr="another_value">more child text, appended text!</child_2>
    </parent>
</root>

Answer 3

我已經修改了extractNumbers函數和其他代碼，以根據讀入的文件生成相對xpath。

import xml.etree.ElementTree as ET

def extractNumbers(path, node):
    nums = []
    # You'll want to store a relative, rather than an absolute path.
    if not path: # This is the root node, store the // Predicate to look at all root's children.
        path = ".//"
    else: # This is not the root node
        if 'month' in node.attrib:
            if node.attrib['month'] in ['05', '06']:
                return nums

        path += node.tag
        if 'name' in node.keys():
            path += '[@name="{:s}"]/'.format(node.attrib['name'])
        elif 'year' in node.keys():
            path += '[@month="{:s}"]/'.format(node.attrib['month'])
        try:
            num = float(node.text)
            nums.append((path, num) )
        except (ValueError, TypeError):
            pass
    # Descend into the node's child nodes
    for e in list(node):
        nums.extend( extractNumbers(path, e) )
    return nums

tree = ET.parse('jerry.xml')
nums = extractNumbers('', tree.getroot())

此時，您有一個填充了“path，num”元組的nums列表。 您將要將路徑寫入csv。 在下文中，我假設您事先知道Text1，Text2和Text3值，因此我在每行中寫了'foo'，'bar'，'baz'。

import csv
# Write the CSV file with the data found from extractNumbers
with open('records.csv', 'w') as records:
    writer = csv.writer(records, delimiter=';')
    writer.writerow(['Path', 'Text1', 'Text2', 'Text3'])
    for entry in nums:
        # Ensure that you're writing a relative xpath
        rel_path = entry[0]
        # you will want to "Text1", 'foo' below, to be an appropriate value, as it will be written into the xml below
        writer.writerow([rel_path, 'foo', 'bar', 'baz'])

您現在將擁有以下CSV文件

Path;Text1;Text2;Text3
".//country[@name=""Peru""]/rank";foo;bar;baz
".//country[@name=""Peru""]/gdpnp";foo;bar;baz
".//country[@name=""Singapore""]/rank";foo;bar;baz
".//country[@name=""Singapore""]/gdpnp";foo;bar;baz

在以下代碼中，您將讀取csv文件讀取CSV文件，並使用PATH列更改適當的值

import csv
import xml.etree.ElementTree as ET
with open('records.csv', 'r') as records:
    reader = csv.reader(records, delimiter=';')
    for row in reader:
        if reader.line_num == 1: continue # skip the row of headers
        for data in tree.findall(row[0]):
            data.text = row[1]
tree.write('jerry_new.xml')

您將在jerry_new.xml中獲得以下結果

<data>
    <country name="Peru">
        <rank updated="yes">foo</rank>
        <language>english</language>
        <currency>1.21$/kg</currency>
        <gdppc month="06">141100</gdppc>
        <gdpnp month="10">foo</gdpnp>
        <neighbor direction="E" name="Austria" />
        <neighbor direction="W" name="Switzerland" />
    </country>
    <country name="Singapore">
        <rank updated="yes">foo</rank>
        <language>english</language>
        <currency>4.1$/kg</currency>
        <gdppc month="05">59900</gdppc>
        <gdpnp month="08">foo</gdpnp>
        <neighbor direction="N" name="Malaysia" />
    </country>
</data>