"""This module contains a code example related to
Think Python, 2nd Edition
by Allen Downey
http://thinkpython2.com
Copyright 2015 Allen Downey
License: http://creativecommons.org/licenses/by/4.0/
"""
from __future__ import print_function, division
from analyze_book1 import process_file
def subtract(d1, d2):
"""Returns a set of all keys that appear in d1 but not d2.
d1, d2: dictionaries
"""
return set(d1) - set(d2)
def main():
hist = process_file('158-0.txt', skip_header=True)
words = process_file('words.txt', skip_header=False)
diff = subtract(hist, words)
print("The words in the book that aren't in the word list are:")
for word in diff:
print(word, end=' ')
if __name__ == '__main__':
main()
