Get word frequency distributions using NLTK

import nltk
from nltk.tokenize import RegexpTokenizer
from nltk.corpus import stopwords

with open('sdlp.txt','r') as ip_file:
    text = ip_file.read()
    
    tokenizer = RegexpTokenizer('\s+', gaps=True)
    tokens = tokenizer.tokenize(text)
    stop = set(stopwords.words('english'))
    
    list_of_words = [i.lower() for i in tokens if i.lower() not in stop and i.isalpha()]
    
    wordfreqdist = nltk.FreqDist(list_of_words)
    mostcommon = wordfreqdist.most_common(30)
    print(mostcommon)