scikit-learn .predict() default threshold

Question

I\'m working on a classification problem with unbalanced classes (5% 1\'s). I want to predict the class, not the probability.

In a binary classification problem, is

Answer 1

The threshold can be set using clf.predict_proba()

for example:

from sklearn.tree import DecisionTreeClassifier
clf = DecisionTreeClassifier(random_state = 2)
clf.fit(X_train,y_train)
# y_pred = clf.predict(X_test)  # default threshold is 0.5
y_pred = (clf.predict_proba(X_test)[:,1] >= 0.3).astype(bool) # set threshold as 0.3