chapter 4: SGDRegressor(tol=-np.infty) is not accepted by the module

hi Aurelien,
i've read the code of In[46], chapter4, but when i copied the code to jupyter and then it turned out to be an error like:
"InvalidParameterError: The 'tol' parameter of SGDRegressor must be a float in the range [0.0, inf) or None. Got -inf instead.
"
i've already knew the SGDRegressor has a default value of 1e-03, but would you like to explain the error and what's your purpose of -np.infty?
thank you very much for your patience.
Francisco