NameError: name 'rmse' is not defined

I’ve imported all libraries as shown in many examples:
from fastai.vision import *
from fastai.tabular import *
from fastai import *

When I try to execute
learn = tabular_learner(data, layers=[200,50], ps=[0.001,0.01], emb_drop=0.04,
y_range=y_range, metrics=rmse)

I get:
NameError: name ‘rmse’ is not defined

I have fastai version 1.0.34

What is the problem here? how can I specify the metric to be root mean square error?

It’s probably because you have an old version, you should upgrade your library.