Hello,
I am trying to make a use of the Python-Stata interface in Stata foreach loop. My loop is shown below:

Code:
foreach a1 of local alphaGrid {

python: a = float(Macro.getLocal("a1"))

// predict using the best value for alpha
python: mnb = MultinomialNB(alpha = a, class_prior = None, fit_prior = True)

// model Accuracy, how often is the MultinomialNB classifier correct?
python: Y_mnb_pred = mnb.fit(X_train, np.ravel(Y_train)).predict(X.iloc[:, :-1])

// right now Y_mnb_best_pred is a numpy array; so change it into a list
python: Y_mnb_pred = Y_mnb_pred.tolist()

// transfer the python variable Y_mnb_best_pred as the Stata variable 'yBestPred'
python: Data.setObsTotal(nobs)
python: Data.addVarFloat('yPred')
python: Data.store(var = 'yPred', obs = None, val = Y_mnb_pred)

generate correct yPred == category
tabulate correct
summarize correct
`accuracy' = r(mean)

replace Accuracy = `accuracy' in `i'
replace Alpha = `a1' in `i'

// update the counter i
local i = `++i' 
drop yPred 

}
and this is generating an error, the error message is "variable yPred already defined".
I thought I would be fine with this since I am doing -drop yPred- at the end of the loop?
How can I fix this error?

Thank you,