medium_queryset_evaluation_caching_1.py

# The following will create two QuerySet's, evaluate them, and throw them away 
# because they are not saving the queryset anywhere to reuse them later.
print([e.headline for e in Entry.objects.all()])
print([e.pub_date for e in Entry.objects.all()])

# Following code saves QuerySet in a variable. When it evaluates, 
# it saves the results to its cache(_result_cache). 
queryset = Entry.objects.all()
# evaluation with iteration.
for each in queryset:
    print(each.headline)
    
# Using cache from previous evaluation.
for each in queryset:
    print(each.id)