计算文件Python中的大写字母数？

Question

我正在尝试从包含文本数据的文本文件中计算唯一大写字母的数量。 我已经完成了从文件中计算大写字母的工作，但在如何计算唯一的大写字母方面需要您的帮助。

这是我尝试过的：

with open('demo.txt') as countletter:
    count = 0
    text = countletter.read()
    for character in text:
        if character.isupper():
            count += 1
print(count) 

Answer 1

您需要跟踪已经出现的大写字母。 使用 set 是一个可行的解决方案。

letters = set()
with open('demo.txt') as countletter:
    count = 0
    text = countletter.read()
    for character in text:
        if character.isupper():
            count += 1
            letters.add(character)
print(count)

非常紧凑的解决方案：

with open('demo.txt') as countletter:
    count = sum(character.isupper() for character in set(countletter.read()))
    print(count)

Answer 2

使用集合解决

unique_capital_letters = set()
with open('demo.txt') as countletter:
    text = countletter.read()
    for character in text:
        if character.isupper():
            unique_capital_letters.add(character)

number_of_unique_occurrences = len(unique_capital_letters)
print(number_of_unique_occurrences)

Answer 3

将所有字符添加到列表中。 然后用它创建一个集合并取它的长度。 这将为您提供独特的大写字符。 像下面这样：

with open('demo.txt') as countletter:
    char_list = list()
    count = 0
    text = countletter.read()
    for character in text:
        if character.isupper():
            #append the capitals
            char_list.append(character)

#create a set and get its length
print(len(set(char_list))) 

Answer 4

您还需要记录所有已经出现的大写字母。

就像是

CapitalChar=''
with open('demo.txt') as countletter:
    count = 0
    text = countletter.read()
    for character in text:
        if character.isupper() and not in CapitalChar:
            CapitalChar=CapitalChar + character
            count += 1
print(count) 

Answer 5

其他答案很好，只是想指出您可以使用Counter使生活更轻松：

from collections import Counter

with open('demo.txt') as countletter:
    unique = Counter(countletter.read())
    unique_capital_letters = {char: count for char, count in unique.items() if char.isupper()}

Answer 6

这里已经发布了一些完美的答案，但为了方便起见，这里有一种非常紧凑的方法来实现它，只需使用常规 python：

with open('demo.txt') as countletter:
  count = sum(character.isupper() for character in set(countletter.read()))

集合保证每个元素都是唯一的，并且使用 sum 就像我做的广告一样，每次字符为大写时都会计数

Answer 7

类似于@Eric 的回答，但使用map函数代替：

with open('demo.txt') as countletter:
    count = sum(map(str.isupper, set(countletter.read())))

Answer 8

有很多方法可以实现您的目标。 人们肯定会根据您的代码逻辑为您提供一种方法。 在这里，我为您提供了一种使用列表推导式 synthax 实现目标的新方法。

with open('demo.txt') as f:
   text = f.read()
   count = len(set([character for character in text if character.isupper()]))

print(count)