<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Create a function to search a given string for the first vowel.
<|im_end|>
<|im_start|>assistant
def first_vowel(string): 
    index = 0
    for char in string:
        if char in ["a", "e", "i", "o", "u"]: 
            return index
        else: 
            index+= 1 
    return -1<|im_end|>
