Train a RNN with strings using positive and negative samples
I think Sequence Classification with LSTM Recurrent Neural Networks in Python with Keras is one of the best tutorial available for this task. It does sentiment analysis on IMDB Dataset and is the simplest to understand. Also, it uses Keras framework which I use right now because of it's simplicity and it's online support and documentation available. The RNN of keras has multiple options which you can explore based on your requirement. Also, keras make it real easy to use an optimizer from a wide variety of options.