Entire text is matched but not able to group in named groups - regex

Question

I have following example text:
my_app|key1=value1|user_id=testuser|ip_address=10.10.10.10
I want to extract sub-fields from it in following way:
appName = my_app,
[
{key = key1, value = value1},
{key = user_id, value = testuser},
{key = ip_address, value = 10.10.10.10}
]
I have written following regex for doing this:
(?<appName>\w+)\|(((?<key>\w+)?(?<equals>=)(?<value>[^\|]+))\|?)+
It matches the entire text but is not able to group it correctly in named groups.
Tried testing it on https://regex101.com/
What am I missing here?

Answer 1

I think the main problem you have is trying to write a regex that matches ALL the key=value pairs. That's not the way to do it. The correct way is based on a pattern that matches ONLY ONE key=value, but is applied by a function that finds all accurances of the pattern. Every languages supplies such a function. Here's the code in Python for example:
import re
txt = 'my_app|key1=value1|user_id=testuser|ip_address=10.10.10.10'
pairs = re.findall(r'(\w+)=([^|]+)', txt)
print(pairs)
This gives:
[('key1', 'value1'), ('user_id', 'testuser'), ('ip_address', '10.10.10.10')]
The pattern matches a key consisting of alpha-numeric chars - (\w+) with a value. The value is designated by ([^|]+), that is everything but a vertical line, because the value can have non-alpha numeric values, such a dot in the ip address.
Mind the findall function. There's a search function to catch a pattern once, and there's a findall function to catch all the patterns within the text.
I tested it on regex101 and it worked.
I must comment, though, that the specific text pattern you work on doesn't require regex. All high level languages supply a split function. You can split by vertical line, and then each slice you get (expcept the first one) you split again by the equal sign.

Answer 2

Use the PyPi regex module with the following code:
import regex
s = "my_app|key1=value1|user_id=testuser|ip_address=10.10.10.10"
rx = r"(?<appName>\w+)(?:\|(?<key>\w+)=(?<value>[^|]+))+"
print( [(m.group("appName"), dict(zip(m.captures("key"),m.captures("value")))) for m in regex.finditer(rx, s)] )
# => [('my_app', {'ip_address': '10.10.10.10', 'key1': 'value1', 'user_id': 'testuser'})]
See the Python demo online.
The .captures property contains all the values captured into a group at all the iterations.

Answer 3

Not sure, but maybe regular expression might be unnecessary, and splitting similar to,
data='my_app|key1=value1|user_id=testuser|ip_address=10.10.10.10'
x= data.split('|')
appName = []
for index,item in enumerate(x):
if index>0:
element = item.split('=')
temp = {"key":element[0],"value":element[1]}
appName.append(temp)
appName = str(x[0] + ',' + str(appName))
print(appName)
might return an output similar to the desired output:
my_app,[{'key': 'key1', 'value': 'value1'}, {'key': 'user_id', 'value': 'testuser'}, {'key': 'ip_address', 'value': '10.10.10.10'}]
using dict:
temp = {"key":element[0],"value":element[1]}
temp can be modified to other desired data structure that you like to have.