sklearn is a commonly used third-party python module in machine learning, URL: http://scikit-learn.org/stable/index.html , which encapsulates some commonly used machine learning methods. When performing machine learning tasks, It is not necessary for everyone to implement all the algorithms, and most machine learning tasks can be implemented by simply calling the modules in sklearn.
Machine learning tasks usually include Classification and Regression. Commonly used classifiers include SVM, KNN, Bayesian, linear regression, logistic regression, decision tree, random forest, xgboost, GBDT, boosting, and neural network NN.
Common dimensionality reduction methods include TF-IDF, topic model LDA, principal component analysis PCA, etc.