Extracting numerical value from sentiment classifier

Question

I have this code, and want to extract out just the number. I tried QuantityMagnitude and a transformation rule.

In[1]:= Normal[Classify["Sentiment", "I love this book.", "Probabilities"] 100][[1]]

Out[1]= "Positive" -> 72.8592

Answer 1

Classify["Sentiment", "I love this book.", "Probabilities"]["Positive"]
(* Out: 0.728592 *)

%*100
(* Out: 72.8592 *)

Answer 2

Whenever you have this kind of problem, use FullForm to figure out what you actually have. Start with your statement, assign it a name, and look at the FullForm:

sol = Normal[Classify["Sentiment", "I love this book.", "Probabilities"] 100][[1]]
sol//FullForm
Rule["Positive",72.85922417349849`]

so you need to extract the number from the Rule. This can be done several ways:

sol[[2]]
"Positive" /. sol

both return your desired number.