Choosing time_step for LSTM
Arrays input into the LSTM have shape: (N_SAMPLES, SEQUENCE_LENGTH, N_FEATURES).
I am trying to reshape my input for my LSTM Network.
I have a training data of train_x (20214000 columns x 9 rows) and train_y (20214000 columns x 1 row).
How do I reshape my train_x such that I can feed it into my RNN? 
I have 9 features so it would be something like: 
train_x.reshape(?,?,9) and 
train_y.reshape(?,?,1)