Python技术问询：如何正确判断列表中字母是否大写并统计数量

首先，你的代码存在几个关键问题，修正后的完整可运行代码如下：

#  Write a Python function to count how many letters in a string are in uppercase.

print("Hey, do you wanna see a cool trick I can do? I can count how many letters in a list of letters are uppercase!")
print("Here, I can prove it!")
print("Gimme a list of letters!")

letter = input("Enter a list of letters, seperating each by a comma. (put both uppercase and lowercase!) ")
letter_list = letter.split(",")
print("The list you gave was...")
print(letter_list)
print("And if we seperate those, we get...")
for letter in letter_list:
    print(letter)
    
print("Now, I'm going to count how many of those are uppercase!")

# 初始化计数变量
capital = 0
for letter in letter_list:
    # 去除元素前后空格后，调用isupper()方法判断
    if letter.strip().isupper():
        capital += 1

print(f"Total uppercase letters: {capital}")

问题解析： #

• 未初始化计数变量：capital在累加前没有设置初始值，会触发NameError，必须先赋值capital = 0
• 错误调用字符串方法：isupper是字符串的内置方法，必须通过括号()调用，直接写letter.isupper只是引用方法对象，永远不会等于True，正确写法是letter.isupper()
• 未处理输入空格：用户输入时可能在逗号后加空格（比如A, b, C），split后的元素会包含空格，导致isupper()返回False，用letter.strip()可以去除元素前后的空白字符，确保判断准确

内容的提问来源于stack exchange，提问作者JuicyMango17