What is the shape of the vector after it passes through the TfidfVecorizer fit_transform() method?
The inverse document frequency transformation of TFIDF does not affect the shape of your vector. The shape is only altered during the tokenization phase which, in your case, results in a shape of (4, 9). The inverse document frequency portion only scales your existing features in accordance with how frequently these tokens arise elsewhere in your corpus. This can be thought as a one-to-one mapping of your original term-frequency vector (the tokenized corpus) to the tfidf vector (scaled using information on how frequent your vectors tokens exist elsewhere in your corpus).