如何用Python正则表达式提取TNS Ping输出中的主机信息？

问题 #

需要从TNS Ping的输出数据中提取所有主机信息，但原正则表达式无法正确匹配，也无法提取多个结果。

示例数据与原代码 #

DATA="""
TNS Ping Utility for Linux: Version 19.0.0.0.0 - Production on 20-SEP-2023 12:13:43

Copyright (c) 1997, 2022, Oracle.  All rights reserved.

Used parameter files:
/oracle/rdbms/19.2/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (SDU=32767)(SEND_BUF_SIZE=16777216)(RECV_BUF_SIZE=16777216) (ADDRESS = (PROTOCOL = TCPS)(HOST = host1-1-ia2-vip.world.net)(PORT = 1523)) (ADDRESS = (PROTOCOL = TCPS)(HOST = host2-2-ia2-vip.world.net)(PORT = 1523)) (LOAD_BALANCE = YES) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = TESTDB92)))
OK (50 msec)
"""

# 原正则表达式无法匹配目标内容
m = re.search('HOST\s\w+\s(\w+)', DATA)
m.group(1)

期望输出 #

host1-1-ia2-vip.world.net
host2-2-ia2-vip.world.net

解决方法 #

原正则表达式存在两个问题：

1. \w+ 仅匹配字母、数字和下划线，无法覆盖主机名中的连字符（-）和点号（.）
2. re.search 仅返回第一个匹配结果，无法提取所有主机名

修正后的代码 #

import re

DATA="""
TNS Ping Utility for Linux: Version 19.0.0.0.0 - Production on 20-SEP-2023 12:13:43

Copyright (c) 1997, 2022, Oracle.  All rights reserved.

Used parameter files:
/oracle/rdbms/19.2/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (SDU=32767)(SEND_BUF_SIZE=16777216)(RECV_BUF_SIZE=16777216) (ADDRESS = (PROTOCOL = TCPS)(HOST = host1-1-ia2-vip.world.net)(PORT = 1523)) (ADDRESS = (PROTOCOL = TCPS)(HOST = host2-2-ia2-vip.world.net)(PORT = 1523)) (LOAD_BALANCE = YES) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = TESTDB92)))
OK (50 msec)
"""

# 匹配所有HOST字段后的主机名
hosts = re.findall(r'HOST\s*=\s*([\w.-]+)', DATA)

# 打印结果
for host in hosts:
    print(host)

正则表达式说明 #

• HOST\s*=\s*：匹配 HOST = 模式，\s* 兼容前后任意数量的空白字符（避免因空格数量不同导致匹配失败）
• ([\w.-]+)：捕获主机名，[\w.-] 允许匹配字母、数字、下划线、连字符和点号，覆盖标准主机名的合法字符

运行结果 #

host1-1-ia2-vip.world.net
host2-2-ia2-vip.world.net

内容的提问来源于stack exchange，提问作者user9599919