Django get_or_create ValueError - django

Question

Trying to add rows from a DataFrame into Django model.
models.py:
class CreditIndex_TEST(models.Model):
loanBook = models.ForeignKey(LoanBooks, on_delete=models.CASCADE)
run_date = models.DateField()
index_date = models.DateField()
index_CD = models.IntegerField()
Index_value = models.FloatField()
class Meta:
constraints = [
models.UniqueConstraint(fields= ['loanBook','run_date','index_date','index_CD'], name='unique_CreditIndexPair')
]
views.py:
for index, row in tempDf.iterrows():
obj, created = CreditIndex_TEST.objects.get_or_create(
loanBook=dbname,
run_date= run_date,
index_date=row['Date'],
index_CD=1,
Index_value=row['CreditIndex_CD1']
)
ERROR::
ValueError: Field 'id' expected a number but got 'Botswana_TU'.
I don't understand why I am being asked to specify id. The record I am trying to add to the model does not exist and therefore Django should create it and assign id, not expect it from me?
EDIT (full traceback):
Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/django/core/handlers/exception.py", line 34, in inner
response = get_response(request)
File "/usr/local/lib/python3.7/site-packages/django/core/handlers/base.py", line 115, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/usr/local/lib/python3.7/site-packages/django/core/handlers/base.py", line 113, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Users/gunthermarais/credit-risk/django/RiskLab/Provisions/views.py", line 48, in macroGUI
Index_value=row['CreditIndex_CD1']
File "/usr/local/lib/python3.7/site-packages/django/db/models/manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/usr/local/lib/python3.7/site-packages/django/db/models/query.py", line 575, in update_or_create
obj = self.select_for_update().get(**kwargs)
File "/usr/local/lib/python3.7/site-packages/django/db/models/query.py", line 404, in get
clone = self._chain() if self.query.combinator else self.filter(*args, **kwargs)
File "/usr/local/lib/python3.7/site-packages/django/db/models/query.py", line 904, in filter
return self._filter_or_exclude(False, *args, **kwargs)
File "/usr/local/lib/python3.7/site-packages/django/db/models/query.py", line 923, in _filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "/usr/local/lib/python3.7/site-packages/django/db/models/sql/query.py", line 1350, in add_q
clause, _ = self._add_q(q_object, self.used_aliases)
File "/usr/local/lib/python3.7/site-packages/django/db/models/sql/query.py", line 1381, in _add_q
check_filterable=check_filterable,
File "/usr/local/lib/python3.7/site-packages/django/db/models/sql/query.py", line 1311, in build_filter
condition = self.build_lookup(lookups, col, value)
File "/usr/local/lib/python3.7/site-packages/django/db/models/sql/query.py", line 1165, in build_lookup
lookup = lookup_class(lhs, rhs)
File "/usr/local/lib/python3.7/site-packages/django/db/models/lookups.py", line 22, in __init__
self.rhs = self.get_prep_lookup()
File "/usr/local/lib/python3.7/site-packages/django/db/models/fields/related_lookups.py", line 115, in get_prep_lookup
self.rhs = target_field.get_prep_value(self.rhs)
File "/usr/local/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 1776, in get_prep_value
) from e
ValueError: Field 'id' expected a number but got 'Botswana_TU'.