python - 如何检查排列是否具有相等的奇偶性？

我正在寻找一种方法来检查2个排列(由列表表示)是否与相同parity 。请注意，我对它们是否是偶数或奇数奇偶性不感兴趣，而只是对它们相等。

我是Python的新手，下面给出了我的幼稚解决方案作为答复。我期待Python专家向我展示一些很酷的技巧，以更少，更优雅的Python代码实现相同的目的。

最佳答案

先前答案的一个较小变体-复制perm1，并保存数组查找。

def arePermsEqualParity(perm0, perm1):
    """Check if 2 permutations are of equal parity.

    Assume that both permutation lists are of equal length
    and have the same elements. No need to check for these
    conditions.
    """
    perm1 = perm1[:] ## copy this list so we don't mutate the original

    transCount = 0
    for loc in range(len(perm0) - 1):                         # Do (len - 1) transpositions
        p0 = perm0[loc]
        p1 = perm1[loc]
        if p0 != p1:
            sloc = perm1[loc:].index(p0)+loc          # Find position in perm1
            perm1[loc], perm1[sloc] = p0, p1          # Swap in perm1
            transCount += 1

    # Even number of transpositions means equal parity
    if (transCount % 2) == 0:
        return True
    else:
        return False