removed trailing spaces

Author: PoojanSmart

Diff for: machine_learning/loss_functions/perplexity_loss.py

@@ -1,9 +1,9 @@
 """
-Compute the Perplexity which useful in predicting language model 
+Compute the Perplexity which useful in predicting language model
 accuracy in Natural Language Processing (NLP.)
 Perplexity is measure of how certain the model in its predictions.
 
-Formula : 
+Formula :
 
 Perplexity Loss = exp(-1/N (Σ ln(p(x)))