What is the author's tone in Life and Death in Shanghai by Nien Cheng?

The tone of the novel is generally upbeat, despite the events that unfold. Cheng says that she is generally a positive and happy person. No matter what happens to her, Cheng works hard to stay mentally alert and fit throughout her imprisonment. She will perform mental and physical exercises in an effort to remain calm and positive. It is her positive attitude that she attributes as the reason why and how she survived all the years in prison and in the consequent environment after her release.