How to initialize an indexed Parameter with data from a dictionary - pandas

Question

I'm working with two blocks, one to use pandas to import data from a .csv file and another one to use this information to construct variable values.
The first block is working fine, I'm able to construct a table with indexed values (in this case is Energy Tariff prices):
import pandas as pd
df_1 = pd.read_csv('time_tff_data.csv', sep=';', usecols=['time', 'tff'], index_col='time', header=0)
data_Tariff = {
'tff':{'time': df_1['tff'].to_dict()} #Set of tariff prices
}
data = {None: dict(tariff=data_Tariff)}
The problem is that on the other block, the one that I need to use the data, I'm not able to initialize a parameter with the data within the dictionary. Altough I'm using Pyomo (for optimization) my question isn't about Pyomo itself, but about how to initialize a Parameter with the data stored in a dictionary (self.tff):
from pyomo.environ import *
from data import data_Tariff
from pyomo.environ import SimpleBlock
class tariff(SimpleBlock):
def __init__(self, *args, **kwds):
super().__init__(*args, **kwds)
self.time = Set()
self.Tmax = Param(self.time, doc='Maximum tariff price', default=1.06, multable=True)
self.Tmin = Param(self.time, doc='Minimum tariff price', default=0.39, multable=True)
self.tff = Param(self.time, doc='Set of tariff prices', default=data_Tariff['tff'], mutable=True)
self.Tc = Var(self.time, doc='Tariff priority index', initialize=0)
def _Tc(m, t):
if tff is not None:
return (m.Tc[t] == (m.Tmax-m.tff[t])/(m.Tmax-m.Tmin) for t in m.time)
return Constraint.Skip
self.Tc = Constraint(self.time, rule=_Tc, doc='Tariff priority index')
My question is: how do I import tariff data "tff[t]" from the data block, since the set is idexed by time [t]?

Answer 1

Couple quick observations...
First, you should be using the keyword initialize not default to initialize from a collection. Also, I can't see why you would make this mutable, so you might remove that. Try:
self.tff = Param(self.time, doc='Set of tariff prices', initialize=data_Tariff['tff'])
This assumes that data_Tariff[tff] returns a properly constructed dictionary that is indexed by self.time
Backing up, I see that you also need to initialize the self.time:
self.time = Set(initialize=data_Tariff[tff].keys())
your constraint... Your constraint appears incorrect. The for t in m.time part is taken care of when you call the rule with a set. It will make a constraint for each value of t. And the check for tff... Probably unnecessary, right? If it is necessary, you need to reference it as self.tff. So:
def _Tc(m, t):
return m.Tc[t] == (m.Tmax-m.tff[t])/(m.Tmax-m.Tmin)
self.Tc = Constraint(self.time, rule=_Tc, doc='Tariff priority index')
Also, your Tmax and Tmin appear to be just constants (not indexed). If that is the case, you can simplify a little bit and just treat them as constants that are regular python variables and take them out of the model declaration, if desired.