how to predict only one class in tensorflow
while preparing the data you can use numpy to set all the data points in class 5 as 1 and the others will be set to as 0 using .
arr = np.where(arr!=5,arr,0)
arr = np.where(arr=5,arr,1) 
and then you can create a binary classifier using Tensorflow to classifiy them while using a binary_crossentropy loss to optimize the classifier
In case you want to predict only one class. Then first you need to label your vectors in such a way that maybe label all those vectors as 'one' which has ground truth 5 and 'zero' to those vectors whose ground truth is not 5. 
how can I implement this in tensorflow using puthon