You should consider a powerful library for machine learning, which gives you the chance to explore new domains of machine learning. As you might know, that machine learning is a very vast field. Its applications are being used in lots of domains like Healthcare, Space-exploration, the Petroleum industry and many more.
You can simply use Scikit learn library for almost every machine learning task.
You can use TensorFlow for deep learning. These two are being used commonly in the industry nowadays.
These libraries are open source, fast and efficient.
Hope this answer helps.