仅根据第一行的queryset过滤器-Django

Question

Tying to filter data using queryset.filter() in Django. but it returns not what I expecting. can someone correct me.
single data cell looks like below.(each line separated by \\n)

1. こちらは1行です。(0.57)\\n
2. こちらは2行です。(0.67)\\n
   
3. こちらは3行です。(0.77)\\n
   
4. こちらは4行です。(0.87)\\n
   
5. こちらは5行です。(0.697)

code like below

queryset = queryset.filter(predicted_result__regex = r"\A.*", predicted_result__contains='(0.5') |\
                   queryset.filter(predicted_result__regex = r"\A.*", predicted_result__contains='(0.6') |\
                   queryset.filter(predicted_result__regex = r"\A.*", predicted_result__contains='(0.7')

output:
this will be considering all 5 lines not only the first line.

target:
only get values contains in first line between score (inside brackets) 0.5 to 0.8. all the other lines should omit.

expected result:

1. こちらは1行です。(0.57)\\n

Answer 1

The problem with your current query is that your 'single data cell' is currently a string. Using a regex to calculate what may or may not be expected will still return the entire string on 'True'. You should separate the 'text' from the 'float' values in order to query more efficiently.

class Model(model):
    descriptor = models.CharField()
    value = models.FloatField()

Now you can actually query the 'value' on it's own.

If you are unable to change the model for whatever reason, you need to do multiple queries and use the union/intersection/difference methods.

fives_queryset = queryset.filter(predicted_result__contains'(0.5')
sixes_queryset = queryset.filter(predicted_result__contains'(0.6')
sevens_queryset = queryset.filter(predicted_result__contains'(0.7')

result_queryset = union(fives_queryset, sixes_queryset, sevens_queryset)