<|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 an iterator in Python that yields only even numbers.
<|im_end|>
<|im_start|>assistant
def even_numbers():
    i = 0
    while True:
        if i % 2 == 0:
            yield i
        i += 1<|im_end|>
