Q.process_query() -- processes the user query, 
		by tokenizing and stemming words.

def process_query(self):
		"""Q.process_query() -- processes the user query, 
		by tokenizing and stemming words.
		"""
		self.query = wt(self.query)
		self.processed_query = []
		for word in self.query:
			if word not in self.stop_words and word not in self.punctuation:
				self.processed_query.append(self.stemmer.stem(word))