re.VERBOSE与dict

Question

我有这个带有一些日志的.txt *我试图将值"-“分配给"user_name”，以防文件没有用户名。但是，在这些情况下，输出dict显示了"user_name":"“。你知道我做错了什么吗？我也尝试过使用item.groupdict"user_name“= "-"，但显然这不是问题的根源.

import re
with open("logdata.txt", "r") as file:
    logdata = file.read()
logs = []
pattern = """
(?P<host>[\d.]+)[-\s]+
(?P<user_name>\w*)\s+
\[(?P<time>[^][]+)\]\s+
"(?P<request>[^"]+)"
"""

for item in re.finditer(pattern,logdata,re.VERBOSE):
    **if item.groupdict("user_name") == None:
        item["user_name"] = '-'**
    logs.append(item.groupdict())

下面是txt的示例：

71.172.239.195 - dooley1853 [21/Jun/2019:15:45:32 -0700] "PUT /cutting-edge HTTP/2.0" 406 24498
180.95.121.94 - mohr6893 [21/Jun/2019:15:45:34 -0700] "PATCH /extensible/reinvent HTTP/1.1" 201 27330
144.23.247.108 - auer7552 [21/Jun/2019:15:45:35 -0700] "POST /extensible/infrastructures/one-to-one/enterprise HTTP/1.1" 100 22921

Answer 1

您可以将item.groupdict()保存在变量中，并在将其附加到logs之前修改其内容。

for item in re.finditer(pattern, logdata, re.VERBOSE):
    params = item.groupdict()
    if params["user_name"] == "":
        params["user_name"] = "-"

    logs.append(params)

或者，您可以更改正则表达式，使第二个组为可选组(?)，但只匹配至少一个字符(\w+)的单词，然后使用default parameter of item.groupdict()。

import re

with open("logdata.txt", "r") as file:
    logdata = file.read()

logs = []
pattern = """
(?P<host>[\d.]+)[-\s]+
(?P<user_name>\w+)?\s+
\[(?P<time>[^][]+)\]\s+
"(?P<request>[^"]+)"
"""

for item in re.finditer(pattern, logdata, re.VERBOSE):
    logs.append(item.groupdict(default="-"))

Answer 2

我用了一种简单的方法

\S+至少一次都不是一个空间

import re
with open("logdata.txt", "r") as file:
    logdata = file.read()
logs = []
pattern = """
(?P<host>[\d.]+)[-\s]+
(?P<user_name>\S+)\s+
\[(?P<time>[^][]+)\]\s+
"(?P<request>[^"]+)"
"""

for item in re.finditer(pattern,logdata,re.VERBOSE):
    logs.append(item.groupdict())

效果很好。我想我有点晚了。