进行群集时，我不断收到代码错误

Question

这是代码

rpart.cv.1 <- train(Recommend~ ., data = train.tokens.df, method = "rpart", trControl = cv.cntrl, tuneLength = 3)

这是我在运行代码时不断遇到的错误

Error in terms.formula(formula, data = data) : duplicated name 'X5.3' in data frame using '.'