Outlier/Anomalies Detection Using Unsupervised Machine Learning

PyOD is one such library to detect outliers in your data. It provides access to more than 20 different algorithms to detect outliers and is compatible with both Python 2 and 3. In the case of outlier detection, the algorithm is used differently. Since we do not know the outliers in advance, KNN is used in an unsupervised learning manner. In this scenario, the algorithm finds the closest K nearest neighbors for every data point and measures the average distance.