推导式速览

nums = [1, 2, 3, 4]
squares = [n*n for n in nums]
even_squares = [n*n for n in nums if n % 2 == 0]
pairs = {(x, y) for x in range(2) for y in range(2)}
index_map = {v: i for i, v in enumerate(nums)}

生成器表达式节省内存

total = sum(n*n for n in range(10_000_000))  # 惰性求值

可读性建议

• 条件尽量前置；嵌套层级超过2层时考虑拆函数
• 推导式只做变换与过滤，复杂逻辑用 for 循环

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