Python - 有效地搜索多个模式的文件行

Question

我正在解析一些大文件，并希望确保我尽可能高效地完成它。 我正在解析的其中一行看起来像这样（Windows安全事件日志4624）：

Security/Microsoft-Windows-Security-Auditing ID [4624] :EventData/Data -> SubjectUserSid = S-1-0-0 SubjectUserName = - SubjectDomainName = - SubjectLogonId = 0x0000000000000000 TargetUserSid = S-1-1-11-1111111111-1111111111-1111111111-1111 TargetUserName = johndoe TargetDomainName = TestDomain TargetLogonId = 0x0000000001111111 LogonType = 3 LogonProcessName = NtLmSsp  AuthenticationPackageName = NTLM WorkstationName = TestWorkstation LogonGuid = {00000000-0000-0000-0000-000000000000} TransmittedServices = - LmPackageName = NTLM V2 KeyLength = 128 ProcessId = 0x0000000000000000 ProcessName = - IpAddress = 1.1.1.1 IpPort = 11111 

我想知道的是，从该行中提取多个字段的最有效方法是什么？ 我可以反复划分线，直到我到达我感兴趣的每个场，但我觉得反复循环线是浪费时间/资源。

是否有一种智能的方式来查看该行仅一次但是拉出，例如，以下字段：

LogonType = 3
TargetUserName = johndoe
TargetUserSid = S-1-1-11-1111111111-1111111111-1111111111-1111

举个例子，我能做的是重复以下过程：

part = line.partition('TargetUserName = ')[2]
username = part.partition(' ')[0]

得到我想要的每个字段（上面的例子只是给我一个用户名），但对我来说再次感觉效率低下。

有没有更好的方法来处理它？

Answer 1

每个字段名称都是一组大写和小写字符。 它们的值与=分开。 每个值都是一组非空白字符。 您可以将re.findall与匹配组一起使用，以查找所有“letters = nonwhitespace”实例。 这将为您提供一个tuple list ，您可以保存或迭代并传递给格式字符串：

>>> s = '''Security/Microsoft-Windows-Security-Auditing ID [4624] :EventData/Data -> SubjectUserSid = S-1-0-0 SubjectUserName = - SubjectDomainName = - SubjectLogonId = 0x0000000000000000 TargetUserSid = S-1-1-11-1111111111-1111111111-1111111111-1111 TargetUserName = johndoe TargetDomainName = TestDomain TargetLogonId = 0x0000000001111111 LogonType = 3 LogonProcessName = NtLmSsp  AuthenticationPackageName = NTLM WorkstationName = TestWorkstation LogonGuid = {00000000-0000-0000-0000-000000000000} TransmittedServices = - LmPackageName = NTLM V2 KeyLength = 128 ProcessId = 0x0000000000000000 ProcessName = - IpAddress = 1.1.1.1 IpPort = 11111 '''
>>> import re
>>> for item in re.findall(r'([A-Za-z]+) = (\S+)', s):
...     print('{} = {}'.format(*item))
...
SubjectUserSid = S-1-0-0
SubjectUserName = -
SubjectDomainName = -
SubjectLogonId = 0x0000000000000000
TargetUserSid = S-1-1-11-1111111111-1111111111-1111111111-1111
TargetUserName = johndoe
TargetDomainName = TestDomain
TargetLogonId = 0x0000000001111111
LogonType = 3
LogonProcessName = NtLmSsp
AuthenticationPackageName = NTLM
WorkstationName = TestWorkstation
LogonGuid = {00000000-0000-0000-0000-000000000000}
TransmittedServices = -
LmPackageName = NTLM
KeyLength = 128
ProcessId = 0x0000000000000000
ProcessName = -
IpAddress = 1.1.1.1
IpPort = 11111

您还可以将其转换为字典以便于访问：

>>> d = dict(re.findall(r'([A-Za-z]+) = (\S+)', s))
>>> d['LogonType']
'3'

Answer 2

    st = 'Security/Microsoft-Windows-Security-Auditing ID [4624] :EventData/Data -> SubjectUserSid = S-1-0-0 SubjectUserName = - SubjectDomainName = - SubjectLogonId = 0x0000000000000000 TargetUserSid = S-1-1-11-1111111111-1111111111-1111111111-1111 TargetUserName = johndoe TargetDomainName = TestDomain TargetLogonId = 0x0000000001111111 LogonType = 3 LogonProcessName = NtLmSsp  AuthenticationPackageName = NTLM WorkstationName = TestWorkstation LogonGuid = {00000000-0000-0000-0000-000000000000} TransmittedServices = - LmPackageName = NTLM V2 KeyLength = 128 ProcessId = 0x0000000000000000 ProcessName = - IpAddress = 1.1.1.1 IpPort = 11111';

using re module and re.findall you can I think get want you want

    import re
    li = re.findall(r'LogonType\s*=\s*\d+|TargetUserName\s*=\s*\w+|TargetUserSid\s*=\s*\w-.*?\s',st,re.MULTILINE| re.DOTALL)
    >>>li
    ['TargetUserSid = S-1-1-11-1111111111-1111111111-1111111111-1111 ', 'TargetUserName = johndoe', 'LogonType = 3']