Frequency of Adjectives in a Text

import nltk, argparse

parser = argparse.ArgumentParser()
parser.add_argument("filename")
options = parser.parse_args()
with open(options.filename, 'r') as f:
    text = f.read()

tokenized = nltk.word_tokenize(text)
tagged = nltk.pos_tag(tokenized)
length = len(tokenized)

adj_words = []
for tag in tagged:
    if tag[1][0] == 'J':
      adj_words.append(tag[0])

adj_dist = nltk.FreqDist(adj_words)
print(adj_dist.most_common(10))
print(adj_dist.plot(100))