Data can be passed to the model ~pyomo.environ.AbstractModel.create_instance method through a series of nested native Python dictionaries. The structure begins with a dictionary of namespaces, with the only required entry being the None namespace. Each namespace contains a dictionary that maps component names to dictionaries of component values. For scalar components, the required data dictionary maps the implicit index None to the desired value:
>>> from pyomo.environ import * >>> m = AbstractModel() >>> m.I = Set() >>> m.p = Param() >>> m.q = Param(m.I) >>> m.r = Param(m.I, m.I, default=0) >>> data = {None: { ... 'I': {None: [1,2,3]}, ... 'p': {None: 100}, ... 'q': {1: 10, 2:20, 3:30}, ... 'r': {(1,1): 110, (1,2): 120, (2,3): 230}, ... }} >>> i = m.create_instance(data) >>> i.pprint() 2 Set Declarations I : Size=1, Index=None, Ordered=Insertion Key : Dimen : Domain : Size : Members None : 1 : Any : 3 : {1, 2, 3} r_index : Size=1, Index=None, Ordered=True Key : Dimen : Domain : Size : Members None : 2 : I*I : 9 : {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)} <BLANKLINE> 3 Param Declarations p : Size=1, Index=None, Domain=Any, Default=None, Mutable=False Key : Value None : 100 q : Size=3, Index=I, Domain=Any, Default=None, Mutable=False Key : Value 1 : 10 2 : 20 3 : 30 r : Size=9, Index=r_index, Domain=Any, Default=0, Mutable=False Key : Value (1, 1) : 110 (1, 2) : 120 (2, 3) : 230 <BLANKLINE> 5 Declarations: I p q r_index r