Question

我有以下输入XML文件，我读取了rel_notes标记并打印出来......运行到以下错误

输入XML：

<rel_notes>
    •   Please move to this build for all further test and development activities 
    •   Please use this as base build to verify compilation and sanity before any check-in happens

</rel_notes>

示例python代码：

file = open('data.xml,'r')
from xml.etree import cElementTree as etree
tree = etree.parse(file)
print('\n'.join(elem.text for elem in tree.iter('rel_notes')))

输出

   print('\n'.join(elem.text for elem in tree.iter('rel_notes')))
 File "C:\python2.7.3\lib\encodings\cp437.py", line 12, in encode
return codecs.charmap_encode(input,errors,encoding_map)
UnicodeEncodeError: 'charmap' codec can't encode character u'\u2022' in position 9: character maps to <undefined>

Answer 1

问题在于printing Unicode to Windows console。即，the character '•'无法在您的控制台使用的cp437中表示。

要重现此问题，请尝试：

print u'\u2022'

你可以设置PYTHONIOENCODING environment variable来指示python用相应的xml char引用替换所有不可代表的字符：

T:\> set PYTHONIOENCODING=cp437:xmlcharrefreplace
T:\> python your_script.py

或者在打印前将文本编码为字节：

print u'\u2022'.encode('cp437', 'xmlcharrefreplace')

^{回答您的初步问题}

To print text of each <build_location/> element：

import sys
from xml.etree import cElementTree as etree

input_file = sys.stdin # filename or file object
tree = etree.parse(input_file)
print('\n'.join(elem.text for elem in tree.iter('build_location')))

如果输入文件很大; iterparse() could be used：

import sys
from xml.etree import cElementTree as etree

input_file = sys.stdin
context = iter(etree.iterparse(input_file, events=('start', 'end')))
_, root = next(context) # get root element
for event, elem in context:
    if event == 'end' and elem.tag == 'build_location':
       print(elem.text)
       root.clear() # free memory

Answer 2

我不认为上面的整个代码段完全有用。但是，当ASCII字符处理不当时，通常会发生UnicodeEncodeError。

实施例

unicode_str = html.decode(<source encoding>)

encoded_str = unicode_str.encode("utf8")

在这个答案中已经清楚地解释了它：Python: Convert Unicode to ASCII without errors

这应该至少解决UnicodeEncodeError。

从XML读取标签并打印它

2 个答案:

实施例