Why isn't my array available for fit_traansform()? What can I do?

train.txt has 3 coulumns. First coulumn and second coulumn were kept in A but I can not use it for fit_transform. Why? Please, help me

from macpath import split

from sklearn.feature_extraction import DictVectorizer



A=[]

B=[]

C=[]

D=[]



vec = DictVectorizer()



with open("train.txt") as f:

    f1=[x.strip() for x in f if x.strip()]

    for x in f1[0:]:

        data=[tuple(x.split())]

        for x in data:

            A.append(x[0]+" "+x[1])

            B.append(x[2])



X=vec.fit_transform(A)