使用 Python RegEx 负前瞻匹配字符串答案

【问题标题】：Matching a string with Python RegEx negative lookahead使用 Python RegEx 负前瞻匹配字符串
【发布时间】：2018-05-16 19:24:52
【问题描述】：

我有一个包含一些内容的文件以及下面的两个“包含”字符串：

some string1
some string2
...

include: "base_pricing_app_model_my_deployment_id.model.lkml"
include: "base_map_layers.model.lkml"
...
some string3
...

子字符串“my_deployment_id”是我需要添加到第二个“包含”字符串的标记，因此文件内容如下所示：

some string1
some string2
...

include: "base_pricing_app_model_my_deployment_id.model.lkml"
include: "base_map_layers_my_deployment_id.model.lkml"
...
some string3

我正在运行 Python 3.5 并使用它的 re 库。这是我尝试替换第二个“包含”字符串的方法：

with fileinput.input(files=(rfi), inplace=True) as cmodf:
for line in cmodf:
    match_no_dep_id = re.sub('^include:\s\"(?!my_deployment_id).*[.]model[.]lkml\"$', line.split('.')[0] + '_' + 'my_deployment_id' + 'model.lkml' + '"',  line)
    print(match_no_dep_id, end='')

但是，两个“包含”条目都被修改了，我最终得到以下内容：

some string1
some string2

include: "base_pricing_app_model_my_deployment_id_my_deployment_id.model.lkml"
include: "base_map_layers_my_deployment_id.model.lkml"

some string3
...

所以我的否定前瞻正则表达式匹配两个字符串，包括已经包含我要否定的令牌的字符串。

我不确定我在这里缺少什么。请帮忙。

谢谢！

【问题讨论】：

标签： python regex-negation negative-lookahead

【解决方案1】：

我相信你想要的是^include:\s\".*(?<!my_deployment_id)\.model\.lkml\"$

使用您的（即^include:\s\"(?!my_deployment_id).*[.]model[.]lkml\"$），您将过滤掉类似include: "include: "my_deployment_id.base_map_layers.model.lkml" 的条目（注意my_deployment_id 出现在.model.lkml 之前而不是正好之前）

In [1]: string1 = 'include: "base_pricing_app_model_my_deployment_id.model.lkml"'
   ...: string2 = 'include: "base_map_layers.model.lkml"'
   ...: 
   ...: import re
   ...: 
   ...: 
   ...: def clean_include(include: str) -> str:
   ...:     return re.sub(
   ...:         '^include:\s\".*(?<!my_deployment_id)\.model\.lkml\"$',
   ...:         include.split('.')[0] + '_' + 'my_deployment_id' + '.model.lkml' + '"',
   ...:         include,
   ...:     )
   ...: 
   ...: 
   ...: print(clean_include(string1))
   ...: print(clean_include(string2))
   ...: 
   ...: 
include: "base_pricing_app_model_my_deployment_id.model.lkml"
include: "base_map_layers_my_deployment_id.model.lkml"

【讨论】：