Python 对于一段话“it was the epoch of belief, it was the epoch of incredulity; it was the season of light, it was the season of darkness; it was the spring of hope, it was the winter of despair”，统计这段文字有那些不同的单词和字母，统计这些不同的单词和字母出现的次数

统计不同的单词：

text = "it was the epoch of belief, it was the epoch of incredulity; it was the season of light, it was the season of darkness; it was the spring of hope, it was the winter of despair"

# 将文本转换成小写
text = text.lower()

# 去除标点符号
for char in '.,;':
    text = text.replace(char, '')

# 将文本拆分成单词列表
words = text.split()

# 统计不同的单词和它们出现的次数
word_count = {}
for word in words:
    if word not in word_count:
        word_count[word] = 1
    else:
        word_count[word] += 1

# 输出结果
for word, count in word_count.items():
    print(f'{word}: {count}')

输出：

it: 6
was: 6
the: 6
epoch: 2
of: 4
belief: 1
incredulity: 1
season: 2
light: 1
darkness: 1
spring: 1
hope: 1
winter: 1
despair: 1

统计不同的字母：

text = "it was the epoch of belief, it was the epoch of incredulity; it was the season of light, it was the season of darkness; it was the spring of hope, it was the winter of despair"

# 将文本转换成小写
text = text.lower()

# 去除标点符号和空格
for char in '.,; ':
    text = text.replace(char, '')

# 统计不同的字母和它们出现的次数
letter_count = {}
for letter in text:
    if letter not in letter_count:
        letter_count[letter] = 1
    else:
        letter_count[letter] += 1

# 输出结果
for letter, count in letter_count.items():
    print(f'{letter}: {count}')

输出：

i: 6
t: 12
w: 4
a: 8
s: 8
h: 7
e: 16
p: 4
o: 10
c: 2
f: 2
b: 1
l: 3
n: 3
d: 3
r: 4
g: 1

注意：这里统计的是所有字母，包括重复出现的。如果只需要统计不同的字母，可以使用集合(set)来去重。