Considering that the var words is a string, you can use nltk lib to split your string in a list of words, and then, perform your tasks.
Something like that:
import nltk
from nltk.probability import FreqDist
words_list = nltk.word_tokenize(words)
words_frquence = FreqDist(words_list)
words_count = len(words_list)
words_unique_count = len(set(words_list))
Now, to remove undesired words or symbols, you will need to apply a func in your string, try that:
import re
def nomalize(string):
clean_string = re.sub(r'Ø|\+','',string) #add '|your symbol' to remove more symbols
return clean_string