How can I inherit params from a parent class and append on the child class?

[André Tavares]

How can I inherit params from a parent class and append on the child class?
I have tried the code below, but received an error.

class Parent(bt.Strategy):
params = {
'p1': '',
'p2': '',
}

class Child(Parent):
params = Parent.params
params.update({
'p3': '',
'p4': '',
})

[ab_trader]

would be nice to have the error posted also.

[André Tavares]

C:\Users\SERVER_OPT1\anaconda3\envs\Denali\python.exe D:/onedrive/AndreTavares/Fundo/Denali/strats/momentumfactor.py --symbols PETR4 BBAS3 ABEV3 "--strat={'symbols_idx': 'ibrx100'}" --start_date=2019-03-01
Traceback (most recent call last):
File "D:/onedrive/AndreTavares/Fundo/Denali/strats/momentumfactor.py", line 40, in <module>
class MomentumFactor(strategy.Strategy):
File "D:/onedrive/AndreTavares/Fundo/Denali/strats/momentumfactor.py", line 44, in MomentumFactor
params.update({
AttributeError: type object 'AutoInfoClass_LineRoot_LineMultiple_LineSeries_Lin' has no attribute 'update'

Process finished with exit code 1

[vladisld]

@André-Tavares said in How can I inherit params from a parent class and append on the child class?:

params.update({

No need to update the params dict. The parameters from the base classes are fused automagically by metaclass during the instantiation. You may take a look at the following post as well: https://community.backtrader.com/topic/2379/difference-between-params-and-p/2