Python-需要将具有大写和小写单词的列表更改为全部小写

Question

My project is pretty basic... I need to take a text file of the gettysburg address and count the number of words and the number of unique words. I've gotten pretty much all the way to the end but its double counting words that are the same just with a capital first letter -- ie But and but. I'm not sure how to fix this :( Here is what I have so far:

def main():
    getty = open('Gettysburgaddress.txt','r')
    lines = getty.readlines()
    getty.close()

    index = 0
    while index < len(lines):
       lines[index] = lines[index].rstrip('\n')
        index += 1

    words = [word for line in lines for word in line.split()]

    size = len(words)

    print('\nThere are', size,'words in the Gettysburg Address.\n')

    unique = list(set(words))

    size_unique = len(unique)

    print('There are', size_unique,'unique words in the Gettysburg Address.\n')

    unique.sort()

    print('Sorted order of unique words:', unique)

    close = input('')

main()

Answer 1

Lowercase the words while collecting them:

words = [word.lower() for line in lines for word in line.split()]

or when creating the set of unique words:

unique = list(set(word.lower() for word in words))

You could simplify your file-loading code a little more:

with open('Gettysburgaddress.txt','r') as getty:
    words = [word.lower() for line in getty for word in line.split()]

This loads the file into a list of lower-cased words in one step, where with statement also takes care of closing the file again.