from pyomo.environ import *

model = AbstractModel()

# @decl:
model.A = Set()
model.B = Set(model.A)
# @:decl
model.C = Set(model.A,model.A)

instance = model.create_instance('set3.dat')

print(sorted(list(instance.A.data()), key=lambda x:x if type(x) is str else str(x)))
print(sorted(list(instance.B[1].data()), key=lambda x:x if type(x) is str else str(x)))
print(sorted(list(instance.B['aaa'].data()), key=lambda x:x if type(x) is str else str(x)))
