为什么Python Regex Wildcard仅匹配newLine

时间:2017-05-09 15:24:38

标签: python regex wildcard logfile

我正在编写一个程序来使用Python RegEx解析日志消息。我已经把所有东西都放在了日志的消息之前。这可以是任意数量的字符类型,因此我假设。*通配符符号将是此问题的最佳解决方案。它匹配除新行之外的所有内容。

但是,当我使用通配符时,唯一返回的是此实例中的新行。有任何想法吗?这是代码和输出:

import os
import re
#Change to and print correct file path
os.chdir('/Users/MacUser/Desktop/regExPython')
print(os.getcwd())

#Iterate and read from syslogexample.txt then print results
line_number = 0
with open('syslogexample.txt', 'r') as syslog:
    log_lines = syslog.readlines()
    for line in log_lines:
        line_number += 1
        print('{:>4} {}'.format(line_number, line.rstrip()))


#Build regex to parse through the data
DATE_RE = r'(\w{3}\s+\d{2})'
TIME_RE = r'(\d{2}:\d{2}:\d{2})'
DEVICE_RE = r'(\S+)'
PROCESS_RE = r'(\S+\s+\S+:)'
MESSAGE_RE = r'(.*)'
CD_RE = r'(\s+)'

Syslog_RE = DATE_RE + CD_RE + \
            TIME_RE + CD_RE + \
            DEVICE_RE + CD_RE + \
            PROCESS_RE + CD_RE + \
            MESSAGE_RE

#Use regex to parse through the data
for line in log_lines:
    m = re.match(Syslog_RE, line)
    if m:
        print(m.groups())

#Printed log Files
      1 apr 29 08:22:13 mac-users-macbook-8 syslogd[49]: asl sender statistics
   2 apr 29 08:22:17 mac-users-macbook-8 com.apple.xpc.launchd[1] (com.apple.xpc.launchd.domain.system):
   3 service "com.apple.emond.aslmanager" tried to hijack endpoint "com.apple.aslmanager" from owner:
   4 com.apple.aslmanager
   5 apr 29 08:22:17 mac-users-macbook-8 com.apple.xpc.launchd[1] (com.apple.xpc.launchd.domain.system):
   6 service "com.apple.emond.aslmanager" tried to hijack endpoint
   7 "com.apple.activity_tracing.cache-delete" from owner: com.apple.aslmanager
   8 apr 29 08:22:17 mac-users-macbook-8 com.apple.xpc.launchd[1] (com.apple.bsd.dirhelper[14184]):
   9 endpoint has been activated through legacy launch(3) apis. please switch to xpc or
  10 bootstrap_check_in(): com.apple.bsd.dirhelper
  11 apr 29 08:22:19 mac-users-macbook-8 com.apple.xpc.launchd[1]
  12 (com.apple.imfoundation.imremoteurlconnectionagent): unknown key for integer:
  13 _dirtyjetsammemorylimit

Parsed Log Files
('apr 29', ' ', '08:22:17', ' ', 'mac-users-macbook-8', ' ', 'com.apple.xpc.launchd[1] (com.apple.xpc.launchd.domain.system):', '\n', '')
('apr 29', ' ', '08:22:17', ' ', 'mac-users-macbook-8', ' ', 'com.apple.xpc.launchd[1] (com.apple.xpc.launchd.domain.system):', '\n', '')
('apr 29', ' ', '08:22:17', ' ', 'mac-users-macbook-8', ' ', 'com.apple.xpc.launchd[1] (com.apple.bsd.dirhelper[14184]):', '\n', '')

Process finished with exit code 0

正如你在最后看到的那样,MESSAGE_RE是唯一印刷的字符是\ n换行符,我认为根本不打印。

全部谢谢!

1 个答案:

答案 0 :(得分:0)

http://www.regex101.com中,正则表达式无法正常工作,因为.*仅捕获直到换行符,这意味着在第3行到第4行的换行符处它停止匹配。也许尝试re.compile()并在re.match()之前编译正则表达式。在python regex模块中有DOTALL标志,使.能够匹配换行符http://docs.python.org/2/library/re.html