1.Opencv
a) http://docs.opencv.org/master/d1/dfb/intro.html
2.scikit-learn（使用最多的）
a) http://scikit-learn.org/stable/modules/linear_model.html#ridge-regression
https://machine-learning-python.kspax.io/Classification/ex1_Recognizing_hand-written_digits.html
a)https://github.com/tensorflow/tensorflow
