Question

在为该任务找到正确的正则表达式时遇到了一些问题，请问我的初学者技能是什么。我想做的是仅从其“可用”：true而不是“可用”：false的行中获取id值。我可以通过re.findall('"id":(\d{13})', line, re.DOTALL)获得所有行的ID（13就是正好匹配13位数字，因为代码中还有其他ID少于13位我不需要）。

{"id":1351572979731,"parent_pid":21741,"available":false,"lou":"678","feature":true,"pub":true,"require":null,"option4":""},
{"id":1351572329731,"parent_pid":21741,"available":false,"lou":"678","feature":true,"pub":true,"require":null,"option4":""},
{"id":1351572943231,"parent_pid":21741,"available":true,"lou":"678","feature":true,"pub":true,"require":null,"option4":""},
{"id":1651572973431,"parent_pid":21741,"available":true,"lou":"678","feature":true,"pub":true,"require":null,"option4":""},

因此最终结果必须为['1651572973431'，'1351572943231']

感谢您的大力帮助

Answer 1

这可能不是一个很好的答案，这取决于您所拥有的。它看起来像，就像您有一个字符串列表，并且您希望从其中的某些字符串获得ID。如果真是这样，那么如果您解析JSON而不是编写拜占庭式正则表达式，它将更加整洁且易于阅读。例如：

import json

# lines is a list of strings:

lines = ['{"id":1351572979731,"parent_pid":21741,"available":false,"lou":"678","feature":true,"pub":true,"require":null,"option4":""}',
'{"id":1351572329731,"parent_pid":21741,"available":false,"lou":"678","feature":true,"pub":true,"require":null,"option4":""}',
'{"id":1351572943231,"parent_pid":21741,"available":true,"lou":"678","feature":true,"pub":true,"require":null,"option4":""}',
'{"id":1651572973431,"parent_pid":21741,"available":true,"lou":"678","feature":true,"pub":true,"require":null,"option4":""}',
]

# parse it and you can use regular python to get what you want:
[line['id'] for line in map(json.loads, lines) if line['available']]

结果

[1351572943231, 1651572973431]

如果您发布的代码是一个长字符串，则可以将其包装在[]中，然后将其解析为具有相同结果的数组：

import json

line = r'{"id":1351572979731,"parent_pid":21741,"available":false,"lou":"678","feature":true,"pub":true,"require":null,"option4":""}, {"id":1351572329731,"parent_pid":21741,"available":false,"lou":"678","feature":true,"pub":true,"require":null,"option4":""}, {"id":1351572943231,"parent_pid":21741,"available":true,"lou":"678","feature":true,"pub":true,"require":null,"option4":""},{"id":1651572973431,"parent_pid":21741,"available":true,"lou":"678","feature":true,"pub":true,"require":null,"option4":""}'

lines = json.loads('[' + line + ']')
[line['id'] for line in lines if line['available']]

Answer 2

这可以满足您的需求

(?<="id":)\d{13}(?=(?:,"[^"]*":[^,]*?)*?,"available":true)

https://regex101.com/r/FseimH/1

扩展

 (?<= "id": )
 \d{13} 
 (?=
      (?: ," [^"]* ": [^,]*? )*?
      ,"available":true
 )

解释

 (?<= "id": )                        # Lookbehind assertion for id
 \d{13}                              # Consume 13 digit id
 (?=                                 # Lookahead assertion
      (?:                                 # Optional sequence
           ,                                   # comma
           " [^"]* "                           # quoted string
           :                                   # colon
           [^,]*?                              # optional non-comma's
      )*?                                 # End sequence, do 0 to many times - 
      ,"available":true                   # until we find  available = true
 )

Answer 3

在这里，我们可以简单地使用“ id”作为左边界，并在捕获组中收集所需的数字：

"id":([0-9]+)

然后，我们可以继续为其添加边界。例如，如果需要13位数字，我们可以简单地：

\"id\":([0-9]{13})

将行与特定字符串匹配以提取值Python Regex

3 个答案: