How to use the pypsa.descriptors.Float function in pypsa

#should be removed and set by program based on generators at bus
    control = String(default="PQ",restricted=["PQ","PV","Slack"])

    #2-d location data (e.g. longitude and latitude; Spatial Reference System Identifier (SRID) set in network.srid)
    x = Float(default=0.)
    y = Float(default=0.)

    p = Series(output=True)
    q = Series(output=True)
    v_mag_pu = Series(default=1., output=True)
    v_ang = Series(output=True)

    v_mag_pu_set = Series(default=1.)

    v_mag_pu_min = Float(default=0.)
    v_mag_pu_max = Float(default=inf)

    #optimisation output for power balance constraint at bus
    marginal_price = Series(output=True)

    #energy carrier could be "AC", "DC", "heat", "gas"
    carrier = String(default="AC")

    sub_network = String(default="")


class SubStation(Common):
    """Placeholder for a group of buses."""

class Region(Common):
    """A group of buses such as a country or county."""

#so if power flows from bus0 to bus1, p0 is positive, p1 is negative
    p0 = Series(output=True)
    p1 = Series(output=True)

    q0 = Series(output=True)
    q1 = Series(output=True)


class Line(Branch):
    """Lines include distribution and transmission lines, overhead lines and cables."""

    list_name = "lines"

    #series impedance z = r + jx in Ohm
    r = Float(0.)
    x = Float(0.)

    #shunt reactance y = g + jb in 1/Ohm
    g = Float(0.)
    b = Float(0.)

    x_pu = Float(0.)
    r_pu = Float(0.)
    g_pu = Float(0.)
    b_pu = Float(0.)

    #voltage angle difference across branches
    v_ang_min = Float(-inf)
    v_ang_max = Float(inf)

    length = Float(default=1.0)
    terrain_factor = Float(default=1.0)

sign = Float(default=1.)
    p = Series(output=True)
    q = Series(output=True)


class Generator(OnePort):

    list_name = "generators"

    control = String(default="PQ",restricted=["PQ","PV","Slack"])

    #i.e. coal, CCGT, onshore wind, PV, CSP,....
    carrier = String(default="")

    #rated power
    p_nom = Float(default=0.0)

    #switch to allow capacity to be extended
    p_nom_extendable = Boolean(False)

    #technical potential
    p_nom_max = Float(inf)
    p_nom_min = Float(0.0)

    #optimised capacity
    p_nom_opt = Float(0.0)

    capital_cost = Float(0.0)
    marginal_cost = Float(0.0)


    #power limits for variable generators, which can change e.g. due

class Store(Common):
    """Generic store, whose capacity may be optimised."""

    list_name = "stores"

    bus = String(default="")
    sign = Float(default=1.)
    p = Series(output=True)
    q = Series(output=True)
    e = Series(output=True)

    p_set = Series()
    q_set = Series()

    #rated energy capacity
    e_nom = Float(default=0.0)

    #switch to allow energy capacity to be extended
    e_nom_extendable = Boolean(False)

    #technical potential
    e_nom_max = Float(inf)

    e_nom_min = Float(0.0)

    #optimised capacity
    e_nom_opt = Float(0.0)

    e_max_pu = Series(default=1.)
    e_min_pu = Series(default=0.)

    e_cyclic = Boolean(False)

#optimised capacity
    e_nom_opt = Float(0.0)

    e_max_pu = Series(default=1.)
    e_min_pu = Series(default=0.)

    e_cyclic = Boolean(False)

    e_initial = Float(0.)

    #cost of increasing e_nom
    capital_cost = Float(0.0)

    #cost of dispatching from the store
    marginal_cost = Float(0.0)

    #per hour per unit loss in state of charge
    standing_loss = Float(0.)



class Load(OnePort):
    """PQ load."""

    list_name = "loads"

    #set sign convention for powers opposite to generator
    sign = Float(-1.)

    p_set = Series()
    q_set = Series()

sign = Float(default=1.)
    p = Series(output=True)
    q = Series(output=True)
    e = Series(output=True)

    p_set = Series()
    q_set = Series()

    #rated energy capacity
    e_nom = Float(default=0.0)

    #switch to allow energy capacity to be extended
    e_nom_extendable = Boolean(False)

    #technical potential
    e_nom_max = Float(inf)

    e_nom_min = Float(0.0)

    #optimised capacity
    e_nom_opt = Float(0.0)

    e_max_pu = Series(default=1.)
    e_min_pu = Series(default=0.)

    e_cyclic = Boolean(False)

    e_initial = Float(0.)

    #cost of increasing e_nom
    capital_cost = Float(0.0)

#maximum state of charge capacity in terms of hours at full output capacity p_nom
    max_hours = Float(1)

    #the minimum power dispatch is negative
    p_min_pu = Series(default=-1)

    #in MW
    inflow = Series()
    spill = Series(output=True)

    efficiency_store = Float(1)

    efficiency_dispatch = Float(1)

    #per hour per unit loss in state of charge
    standing_loss = Float(0.)


class Store(Common):
    """Generic store, whose capacity may be optimised."""

    list_name = "stores"

    bus = String(default="")
    sign = Float(default=1.)
    p = Series(output=True)
    q = Series(output=True)
    e = Series(output=True)

    p_set = Series()
    q_set = Series()

#pi is positive if power is flowing from bus i into the branch
    #so if power flows from bus0 to bus1, p0 is positive, p1 is negative
    p0 = Series(output=True)
    p1 = Series(output=True)

    #limits per unit of p_nom
    p_min_pu = Series(default=0.)
    p_max_pu = Series(default=1.)

    efficiency = Series(default=1.)

    #The set point for p0.
    p_set = Series()

    length = Float(default=1.0)
    terrain_factor = Float(default=1.0)

class ThreePort(Common):
    """Placeholder for 3-winding transformers."""

class ThreeTransformer(ThreePort):
    pass

class LineType(Common):
    """Placeholder for future functionality to automatically generate line
    parameters from standard parameters (e.g. r/km)."""

Type = namedtuple("Type", ['typ', 'name', 'df', 'pnl', 'ind'])

class Network(Basic):
    """
    Network container for all buses, one-ports and branches.

#i.e. coal, CCGT, onshore wind, PV, CSP,....
    carrier = String(default="")

    #rated power
    p_nom = Float(default=0.0)

    #switch to allow capacity to be extended
    p_nom_extendable = Boolean(False)

    #technical potential
    p_nom_max = Float(inf)
    p_nom_min = Float(0.0)

    #optimised capacity
    p_nom_opt = Float(0.0)

    capital_cost = Float(0.0)
    marginal_cost = Float(0.0)


    #power limits for variable generators, which can change e.g. due
    #to weather conditions; per unit to ease multiplication with
    #p_nom, which may be optimised
    p_max_pu = Series(default=1.)
    p_min_pu = Series(default=0.)

    #operator's intended dispatch
    p_set = Series()
    q_set = Series()

list_name = "generators"

    control = String(default="PQ",restricted=["PQ","PV","Slack"])

    #i.e. coal, CCGT, onshore wind, PV, CSP,....
    carrier = String(default="")

    #rated power
    p_nom = Float(default=0.0)

    #switch to allow capacity to be extended
    p_nom_extendable = Boolean(False)

    #technical potential
    p_nom_max = Float(inf)
    p_nom_min = Float(0.0)

    #optimised capacity
    p_nom_opt = Float(0.0)

    capital_cost = Float(0.0)
    marginal_cost = Float(0.0)


    #power limits for variable generators, which can change e.g. due
    #to weather conditions; per unit to ease multiplication with
    #p_nom, which may be optimised
    p_max_pu = Series(default=1.)
    p_min_pu = Series(default=0.)

    #operator's intended dispatch
    p_set = Series()