Updating parameter values

update.py

def update(params_values, grads_values, nn_architecture, learning_rate):
    for layer_idx, layer in enumerate(nn_architecture):
        params_values["W" + str(layer_idx)] -= learning_rate * grads_values["dW" + str(layer_idx)]        
        params_values["b" + str(layer_idx)] -= learning_rate * grads_values["db" + str(layer_idx)]

    return params_values;

This Gist, in the context of https://towardsdatascience.com/lets-code-a-neural-network-in-plain-numpy-ae7e74410795, should be changed to enumerate(nn_architecture, 1) to skip the first index (index 0).