F1_score(average='micro') is equal to calculating accuracy for multiclasification
In classification tasks for which every test case is guaranteed to be assigned to exactly one class, micro-F is equivalent to accuracy. 

The above answer is from:
https://stackoverflow.com/questions/37358496/is-f1-micro-the-same-as-accuracy

More detailed explanation:
https://simonhessner.de/why-are-precision-recall-and-f1-score-equal-when-using-micro-averaging-in-a-multi-class-problem/