Learning Python for Data Science
Both Python and R are extensively used in the field of data science.Though both have their advantages and disadvantages, python has many libraries that are awesome to use for data science purpose. For example, scikit-learn, Keras, Theano, XGBoost, Matplotlib,etc. These make lives so easy for data science.
Yes, analyzing and understanding the code of others can give you a lit of information but you cannot learn until you don't get your hands dirty with some python code. In order to learn how to use python in data science, this link provides an excellent tutorial.