how to output f1-score instead of accuracy

Question

I have the code below, outputting the accuracy. How can I output the F1-score instead? Thanks in advance,

 clf.fit(data_train,target_train)  
preds = clf.predict(data_test)  
# accuracy for the current fold only     
r2score = clf.score(data_test,target_test)

Answer 1

from sklearn.metrics import f1_score
f1_score(data_test,target_test)