Python Sequencematcher 给出不完全匹配

Question

我正在尝试使用 Python 的 SequenceMatcher 查找两个字符串之间的匹配 block 。字符串为 "ABCDPQRUVWXYZ" 和 "PQRABCDUVWXYZ"。但是，当我应用 get_matching_blocks() 时，找不到字符串 "PQR" 作为匹配 block 。

from difflib import SequenceMatcher

str1 = "ABCDPQRUVWXYZ"
str2 = "PQRABCDUVWXYZ"

matchAll = SequenceMatcher(None, str1, str2, False).get_matching_blocks()

for i in range(0, len(matchAll)):
    print(str1[matchAll[i].a: matchAll[i].a + matchAll[i].size])

Answer 1

docs声明:

get_matching_blocks()

Return list of triples describing matching subsequences. Each triple is of the form (i, j, n), and means that a[i:i+n] == b[j:j+n]. The triples are monotonically increasing in i and j.

如果函数返回"PQR"在您的示例中，j不会单调递增，因为它会从 "A" 开始索引 "ABCD"匹配，返回"P"索引 "PQR"匹配。