我能识别小写字母和大写字母，并把它们放在字典中。我需要将大写和小写值连接在一起。

Question

我需要知道一个字符显示了多少次，并将结果保存在字典中。例如：{"e": 8, "s": 7}的意思是"e“显示8次，"s”显示7次。我必须使上下大写的值是相同的。

我设法找出每个字符显示了多少次。我很难把大写字母和小写字母放在一起，而不是分开。

counting_symbols = {}
for letter in "Cryptography is the practice and study of techniques" \
              " for secure communication in the presence of third parties" \
              " called adversaries. More generally, cryptography is about" \
              " constructing and analyzing protocols that prevent third" \
              " parties or the public from reading private messages; various " \
              "aspects in information security such as data confidentiality, " \
              "data integrity, authentication, and non-repudiation are central " \
              "to modern cryptography. Modern cryptography exists at the" \
              " intersection of the disciplines of mathematics, computer science, " \
              "electrical engineering, communication science, and physics. Applications " \
              "of cryptography include electronic commerce, chip-based payment cards, " \
              "digital currencies, computer passwords, and military communications.":
    counting_symbols[letter] = counting_symbols.get(letter, 0) + 1



print(counting_symbols)

这使大写字母和小写字母分开。有人能帮忙让他们联合起来吗？

Answer 1

您只需添加1行代码即可将字母转换为小写：

counting_symbols = {}
for letter in "Cryptography is the practice and study of techniques" \
          " for secure communication in the presence of third parties" \
          " called adversaries. More generally, cryptography is about" \
          " constructing and analyzing protocols that prevent third" \
          " parties or the public from reading private messages; various " \
          "aspects in information security such as data confidentiality, " \
          "data integrity, authentication, and non-repudiation are central " \
          "to modern cryptography. Modern cryptography exists at the" \
          " intersection of the disciplines of mathematics, computer science, " \
          "electrical engineering, communication science, and physics. Applications " \
          "of cryptography include electronic commerce, chip-based payment cards, " \
          "digital currencies, computer passwords, and military communications.":
letter = str.lower(letter)
counting_symbols[letter] = counting_symbols.get(letter, 0) + 1

print(counting_symbols)

Answer 2

可以使用lower()函数降低所有字符，并将其保存到另一个变量中。

使用集合库中的计数器类也是一个很好的实践。计数器对象会自动计数字符串中的字符或列表中的字符串，并将数据保存在字典中。

text = "Cryptography is the practice and study of techniques"
lower_chars = text.lower()

from collections import Counter
counter = Counter(lower_chars)
print(counter)

Answer 3

你计算它们的方式可以更具体。为了给您提供一个伪代码示例：

if(letter == ('S' or 's')):
  num_s = num_s+1

您只需复制和粘贴这一行的每一个字母，例如，在一个函数。最后，你可以返回这些数字。我希望你能明白我算法的要点。您可以通过多种方式实现它，我的算法非常具体。