step-line.py

#in pseudocode, this would be: 
w -= gradient(w) *lr 



#stepping learning function here
#converting this into a function: 
def train_epoch(model, lr, params):
    for xb,yb in dl:
        calc_grad(xb, yb, model)
        for p in params:
            p.data -= p.grad*lr
            p.grad.zero_()