编写一个名为 `count_vowels` 的python函数，接收一个字符串并返回其中元音字母的数量
def count_vowels(string):
  vowels = ['a', 'e', 'i', 'o', 'u']
  count = 0
  for letter in string:
    if letter.lower() in vowels:
      count += 1
      return count
# 测试
print(count_vowels('hello')) # 2
print(count_vowels('world')) # 1
print(count_vowels('aeiou')) # 5
print(count_vowels('')) # 0
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
编写一个名为 `count_vowels` 的python函数，接收一个字符串并返回其中元音字母的数量

### Response:  def count_vowels(string):
    vowel_count = 0
    for letter in string:
        if letter in 'aeiou':
            vowel_count += 1
    return vowel_count
 def count_vowels(string):
    vowel_count = 0
    for letter in string:
        if letter in 'aeiou':
            vowel_count += 1
    return vowel_count
你是一个计算机科学老师，给定一道编程问题，你需要判断模型回答能否解决该问题，分数在0到1之间。标准答案仅作为参考。模型回答中的代码步骤可以和标准答案不同，但一定要是正确的。请按照"得分:"这样的形式输出分数。 编写一个名为 `count_vowels` 的python函数，接收一个字符串并返回其中元音字母的数量 标准回答:def count_vowels(string):
  vowels = ['a', 'e', 'i', 'o', 'u']
  count = 0
  for letter in string:
    if letter.lower() in vowels:
      count += 1
      return count
# 测试
print(count_vowels('hello')) # 2
print(count_vowels('world')) # 1
print(count_vowels('aeiou')) # 5
print(count_vowels('')) # 0  模型回答：'  def count_vowels(string):
    vowel_count = 0
    for letter in string:
        if letter in 'aeiou':
            vowel_count += 1
    return vowel_count'。请针对模型回答给出得分，顺便给出理由：
得分: 0.8

理由: 

模型回答中没有将所有字母转换为小写，可能会因为大小写的差异导致漏掉某些元音字母。在测试用例中没有包含所有可能出现的情况，更全面的测试需要进一步考虑。
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
编写一个名为 `count_vowels` 的python函数，接收一个字符串并返回其中元音字母的数量

### Response: def count_vowels(string):
  vowels = ['a', 'e', 'i', 'o', 'u']
  count = 0
  for letter in string:
    if letter.lower() in vowels:
      count += 1
      return count
# 测试
print(count_vowels('hello')) # 2
print(count_vowels('world')) # 1
print(count_vowels('aeiou')) # 5
print(count_vowels('')) # 0
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
编写一个名为 `count_vowels` 的python函数，接收一个字符串并返回其中元音字母的数量

### Response:  def count_vowels(string):
    vowel_count = 0
    for letter in string:
        if letter in 'aeiou':
            vowel_count += 1
    return vowel_count