Question

我有一些表现良好的xml文件，我想使用正则表达式重新格式化（NOT PARSE！）。目标是让每个<trkpt>对成为oneliner。

以下代码有效，但我想在单个正则表达式替换而不是循环中执行操作，因此我不需要将字符串连接回来。

import re

xml = """
    <trkseg>
      <trkpt lon="-51.2220657617" lat="-30.1072524581">
        <time>2012-08-25T10:20:44Z</time>
        <ele>0</ele>
      </trkpt>
      <trkpt lon="-51.2220657617" lat="-30.1072524581">
        <time>2012-08-25T10:20:44Z</time>
        <ele>0</ele>
      </trkpt>
      <trkpt lon="-51.2220657617" lat="-30.1072524581">
        <time>2012-08-25T10:20:44Z</time>
        <ele>0</ele>
      </trkpt>
    </trkseg>
"""

for trkpt in re.findall('<trkpt.*?</trkpt>', xml, re.DOTALL):
    print re.sub('>\s*<', '><', trkpt, re.DOTALL)

使用sed的答案也会受到欢迎。

感谢您阅读

Answer 1

这个怎么样：

>>> regex = re.compile(
    r"""\n[ \t]*  # Match a newline plus following whitespace
    (?=           # only if... 
     (?:          # ...the following can be matched:
      (?!<trkpt)  #  (unless an opening <trkpt> tag occurs first)
      .           #  any character
     )*           # any number of times,
     </trkpt>     # followed by a closing </trkpt> tag
    )             # End of lookahead""", 
    re.DOTALL | re.VERBOSE)
>>> print regex.sub("", xml)

    <trkseg>
      <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
      <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
      <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
    </trkseg>

Answer 2

这不是你要求的，但是为了成为一个单行，这里有一个单行：

>>> print re.sub(r'(<trkpt.*?</trkpt>)',
                 lambda m: re.sub(r'>\s*<', '><', m.group(1), re.DOTALL),
                 xml, flags=re.DOTALL)

<trkseg>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
</trkseg>

另请注意，如果任何字符串属性包含字符串"<trkpt"，这种方法将会中断，这可能不会发生，但这是不使用真正解析器的问题。

Answer 3

您想保留<trkseg>吗？如果是这样，这可能适合您：

print re.sub('([^gt])>\s*<', '\g<1>><', xml, re.DOTALL)

删除元素之间的所有空格，条件是前一个元素不以t或g结尾。

<trkseg>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44Z</time><ele>0</ele></trkpt>
</trkseg>

Answer 4

另一个单行是

print re.sub("(<trkpt.+?>).*?(<time>.+?</time>).*?(<ele>.+?</ele>).*?(</trkpt>)",
             r'\1\2\3\4', xml, re.DOTALL)

产生

<trkseg>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44</time><ele>0</ele></trkpt>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44</time><ele>0</ele></trkpt>
  <trkpt lon="-51.2220657617" lat="-30.1072524581"><time>2012-08-25T10:20:44</time><ele>0</ele></trkpt>
</trkseg>

这样做的好处是可以轻松更改其他标签。

Python正则表达式删除模式匹配中的空格

4 个答案: