gistfile1.py

from django.db.models import Q
from apps.research.models import Product

"""
`codes` is a list of remaining (str) barcodes from the file.
`excludes` is a list of primary keys which i've already found
"""

minimum_digits = 5
qset = Q()

for code in codes:
    if len(code) > minimum_digits:
        qset |= Q(barcode__startswith=code) | Q(barcode__endswith=code)
print "Finished creating queryset"

products = Product.objects.exclude(pk__in=excludes).filter(qset).distinct()