尝试编写代码，但收到错误:IndexError: string index out of range

Question

我正在尝试写一段简单的代码来检查每个字母: a，e，i，o，u在字符串中存在的次数，但我得到的错误是:字符串索引超出范围。我能做些什么来解决这个问题呢？代码是：

def targ6(str6):
  x = ['a','e','i','o','u']
  s = ""
  for tav in str6:
    for y in range(len(x)):
      if x[y] == tav:
        s[y] += 1
  for y in range(len(x)):
    return ('the letter'+x[tav]+'appears'+s[tav]+'times')


#main
string6=input("enter a string")
print(targ6(string6))

Answer 1

试试这个：

def targ6(str6):
  x = ['a','e','i','o','u']
  s = {k:0 for k in x}
  for tav in str6:
    for y in range(len(x)):
      if x[y] == tav:
        s[tav] += 1 # s[x[y]] += 1
  return s


#main
string6="enter a string"
print(targ6(string6))

输出：

{'a': 1, 'e': 2, 'i': 1, 'o': 0, 'u': 0}

Answer 2

from collections import Counter

def targ6(str6):
    list1 = []
    x = ['a','e','i','o','u']
    for i in str6:  #For character in string
        if i in x:     #If character in vowel list
            list1.append(i)       #Append the character to a list

    for k, v in Counter(list1).items(): #Counter returns a dict with each element's count
        print(k, "appears", v, "times in", str6)
string6 = input("enter a string :")
targ6(string6)

示例：-

enter a string :Hi How are you? Fine?
i appears 2 times in Hi How are you? Fine?
o appears 2 times in Hi How are you? Fine?
a appears 1 times in Hi How are you? Fine?
e appears 2 times in Hi How are you? Fine?
u appears 1 times in Hi How are you? Fine?

Answer 3

• 你不能在Python语言中原地修改字符串(比如s)，而且它们的工作方式肯定不像计数器之类的。
• 如果你发现自己在用Python语言编写for ... in range(len(...))，请停止你正在做的事情。会有更好的方法。
• 一个函数只能返回一次。因为您无论如何都要打印出一些东西，所以我冒失地用print.
• Use、内置函数和方法交换了return！仔细阅读Python文档，它很容易理解，您不必记住所有内容，只需对事物有个感觉，这样您就知道将来该往哪里看了。

def count_vowels(string):
    for vowel in 'aeiou':
        print('the letter', vowel, 'appears', string.count(vowel), 'times')

input_string = input("enter a string: ")
count_vowels(input_string)