Python 实现原地翻转序列的 reverse()

def reverse(seq):
    """原地翻转序列"""
    for i in range(len(seq) >> 1):    # len(seq) >> 1 相当于 len(seq) // 2
        j = ~i    # ~i 相当于 -(i+1)
        seq[i], seq[j] = seq[j], seq[i]