Chapter 4 listing not working in TensorFlow 2

[LucaCerina]

Hello,
I have reached chapter 4 and tried to replicate its notebook, but it doesn't seem to work properly, as it's not learning the proper values. The loss output is 0 from the beginning, so there is probably an issue there in how it's calculated.

I am investigating this issue, so I will come back to you if I find a fix

[LucaCerina]

Found that if weeks go from 1 to 52 it doesn't work. From 0 to 51 it works ok.

[chrismattmann]

thank you @LucaCerina! If you get a chance please provide a PR and we'll look at updating it...