get model object value dynamically by iterating the django model-CodePudding

i want to fetch value dynamically in django model

        users = User.objects.all()
        for user in users:
            print(user.first_name) # works fine
            # now  how to make it dynamic
            onefield = "first_name"
            print(user.onefield)  # come error 
            # and for list of field name
            fieldnames= ["first_name","last_name","email"]
            for i in fieldnames:
                print(user.i) # any shortcut for all value

CodePudding user response：

If the dynamic fields you want to access are strings, then use getattr().

fieldname = "first_name"
print(getattr(user, fieldname))

CodePudding user response：

For the way you are doing in your question

fieldname = "first_name"
print(getattr(user, fieldname))

You can also use other ways to get the values, such as:

fields = User.objects.all().values('first_name')
print(fields)

This returns a QuerySet that returns dictionaries. You can also use more fields

fields = User.objects.all().values('id', 'first_name', 'last_name')
print(fields)
<QuerySet [{'id': 1, 'first_name': 'Barney', 'last_name': 'Stinson'}]>

For unpacking

>>> qs = User.objects.all()
>>> values = ['first_name', 'email']
>>> qs.values(*values)

If you just need one value use values_list with flat=True

fields = User.objects.all().values_list('first_name', flat=True)

This return a tuple with the value