RASA NLU: Can't extract entity - rasa-nlu

Question

I've trained my rasa nlu model in a way that It recognizes the content in between square brackets as pst entity. For the training part, I had covered both the scenarios with more than 50 examples.
There are two scenarios(only space difference):
When I pass http://www.google.comm, 1283923, [9283911,9309212,9283238], it is considering only [ bracket as the pst entity.
When I pass http://www.google.comm, 1283923, [9283911, 9309212, 9283238], it is working fine and recognizing [9283911, 9309212, 9283238] as the pst entity as expected.
For the scenario 1, I've tried all the possible pipelines, but it only recognizes the first square bracket [ as the pst entity
In the response, I am getting this output:
{
'intent': {
'name': None,
'confidence': 0.0
},
'entities': [
{
'start': 0,
'end': 22,
'value': 'http://www.google.comm',
'entity': 'url',
'confidence': 0.8052099168500071,
'extractor': 'ner_crf'
},
{
'start': 24,
'end': 31,
'value': '1283923',
'entity': 'defect_id',
'confidence': 0.8334249141074151,
'extractor': 'ner_crf'
},
{
'start': 33,
'end': 34,
'value': '[',
'entity': 'pst',
'confidence': 0.5615805162522188,
'extractor': 'ner_crf'
}
],
'intent_ranking': [],
'text': 'http://www.google.comm, 1283923, [9283911,9309212,9283238]'
}
So, Can anyone tell me what I am missing in the configuration? The problem is happening because of spacing only, and my model should have the knowledge of spacing as I am providing the training data with both scenarios.

Answer 1

It is good idea to use Regex for your purpose. Rasa NLU supports extraction of Entities by Regex. Normal NLU training data will have something like below
{
"rasa_nlu_data": {
"common_examples": [
{
"text": "Hi",
"intent": "greet",
"entities": []
}]
}
}
You can provide Regex data for training as below in the NLU json file.
{
"rasa_nlu_data": {
"regex_features": [
{
"name": "pst",
"pattern": "\[..*\]"
},
]
}
}
Reference: Regular Expression in Rasal NLU