如何从python regex中排除特定的字符串?

I'm attempting to parse /etc/mtab but exclude /boot. I thought perhaps non-capturing groups would be the way to go, but it doesn't work as I expected. This is the regex I constructed:

我试图解析/etc/mtab但排除/引导。我想也许不抓人的团体会是我的出路，但它并没有像我预期的那样发挥作用。这是我构造的regex:

proc = subprocess.Popen(["ssh", server, "cat", mtab],stdout = subprocess.PIPE)
for line in proc.stdout:
  fsMatch = re.search(r'([\w/:]+) (/([\w/:-]+)|(?:boot)) (nfs|ext3)', line)
  if fsMatch:
    print fsMatch.group(1,2,4)

Output:

输出:

('/dev/sda1', '/boot', 'ext3')
('/dev/mapper/foo1', '/export/foo1', 'ext3')
('/dev/mapper/foo2', '/export/foo2', 'ext3')
('/dev/mapper/foo3', '/export/foo3', 'ext3')
('/dev/mapper/foo4', '/export/foo4', 'ext3')
('/dev/mapper/foo5', '/export/foo5', 'ext3')
('servernfs:/install', '/mnt', 'nfs')

I'm pretty confident the | is wrong (and obviously more is wrong) but have hit a roadblock.

我很有信心|是错误的(显然更多是错误的)，但是遇到了障碍。

I'm looking for all matches for /[\w/:-]+ but exclude matches to /boot

我正在寻找/[\w/:-]+的所有匹配项，但排除对/boot的匹配项

Suggestions?

建议吗?

2 个解决方案

#1

You need to use a negative lookbehind or negative lookahead, described here with a hint below:

你需要使用一个消极的前视或消极的前视，这里有一个提示:

r'^(?!/boot).*$'

If you need to capture that 'servernfs:' one and not 'servernfs:/boot', you'll need to sprinkle in a little '|' and '([a-z]+:)' somewhere at the top (after the '^')

如果您需要捕获“servernfs:“,而不是“servernfs:/ boot”,你需要洒在一个小“|”和“([a - z]+:)”顶部的地方(在“^”)

#2

Just exclude the line:

排除线:

for line in proc.stdout:
  if 'boot' not in line:
      # the rest

However, since mtab is delimited on space, you can just use split:

但是，由于mtab在空间上是分隔的，所以可以使用split:

>>> with open('foo.txt') as f:
...     lines = [line.split(' ') for line in f if 'boot' not in line]
...

#1