Question

所以我正在制作一个程序来创建portmanteaus。我有我需要的代码和功能，我把它们放在一起。

以下是代码：

def portmanteauscore(start, mid, end):
    totallen = len(start) + len(mid) + len(end)
    return totallen - abs((len(start)/totallen) - len(start)) - abs((len(mid)/totallen) - len(mid)) - abs((len(end)/totallen) - len(end))


def portmanteaugenerator(word1, word2, words):
    mid = longest_common_substring(word1, word2)
    start = word1[:word1.index(mid)]
    end = word2[len(mid):]
    if start + mid in words and mid + end in words:
        return start, mid, end


def natalie(words):
    "Find the best Portmanteau word formed from any two of the list of words."
    wordpermutations = list(itertools.permutations(words))
    maxscore, bestnatalie = 0, ''
    for perm in wordpermutations:
        start, mid, end = portmanteaugenerator(perm[0], perm[1], words)
        if portmanteauscore(start, mid, end) > maxscore:
            bestnatalie, maxscore = start + mid + end, portmanteauscore(start, mid, end)
    print bestnatalie
    return bestnatalie


def longest_common_substring(s1, s2):
    m = [[0] * (1 + len(s2)) for i in xrange(1 + len(s1))]
    longest, x_longest = 0, 0
    for x in xrange(1, 1 + len(s1)):
        for y in xrange(1, 1 + len(s2)):
            if s1[x - 1] == s2[y - 1]:
                m[x][y] = m[x - 1][y - 1] + 1
                if m[x][y] > longest:
                    longest = m[x][y]
                    x_longest = x
            else:
                m[x][y] = 0
    return s1[x_longest - longest: x_longest]

但是当我运行代码时，我不断收到此错误消息，

Traceback (most recent call last):
 File "vm_main.py", line 33, in <module>
  import main
   File "/tmp/vmuser_ijxrjleuxj/main.py", line 107, in <module>
   print test_natalie()
  File "/tmp/vmuser_ijxrjleuxj/main.py", line 87, in test_natalie
assert natalie(['adolescent', 'scented', 'centennial', 'always', 'ado']) in        ('adolescented','adolescentennial')
  File "/tmp/vmuser_ijxrjleuxj/main.py", line 67, in natalie
     start,mid,end=portmanteaugenerator(perm[0],perm[1],words)
 TypeError: 'NoneType' object is not iterable

当我返回portmanteau生成器的开始，中间和结束变量时会发生这种情况。当给出一个单词列表时，它应该从两个单词中返回一个portmanteau，这是根据portmanteau得分最好的。

但是由于某种原因我一直都会遇到这种类型错误。我尝试过开始，中间，结束列表，但仍然无法运行。你能帮我么？

Answer 1

最有可能的是，start+mid in words and mid+end in words返回False，因此函数返回if-statement而不是通过None（因为如果某个函数没有返回某些内容，那么默认为None）。

然后你要尝试做类似的事情：

start,mid,end = None

python尝试做的是在这三个变量中拆分None。就像这样做：

one, two, three = (1, 2, 3)

但你不能，因为None不是可迭代的。

Python神秘的错误

1 个答案: