Question

我有两个字符串对的例子

YHFLSPYVY      # answer
   LSPYVYSPR   # prediction
+++******ooo


  YHFLSPYVS    # answer
VEYHFLSPY      # prediction
oo*******++

如上所述，我希望在答案（*）和预测（+）中找到重叠区域（o）和非重叠区域。

我怎样才能用Python做到这一点？

我坚持这个

import re
# This is of example 1
ans = "YHFLSPYVY"
pred= "LSPYVYSPR"
matches = re.finditer(r'(?=(%s))' % re.escape(pred), ans)
print [m.start(1) for m in matches]
#[]

我希望得到的答案是例如：

plus_len = 3
star_len = 6
ooo_len = 3

Answer 1

使用difflib.SequenceMatcher.find_longest_match：

很容易

from difflib import SequenceMatcher

def f(answer, prediction):
    sm = SequenceMatcher(a=answer, b=prediction)
    match = sm.find_longest_match(0, len(answer), 0, len(prediction))
    star_len = match.size
    return (len(answer) - star_len, star_len, len(prediction) - star_len)

该函数返回一个3元组的整数(plus_len, star_len, ooo_len)：

f('YHFLSPYVY', 'LSPYVYSPR') -> (3, 6, 3)
f('YHFLSPYVS', 'VEYHFLSPY') -> (2, 7, 2)

Answer 2

您可以使用difflib：

import difflib

ans = "YHFLSPYVY"
pred = "LSPYVYSPR"

def get_overlap(s1, s2):
     s = difflib.SequenceMatcher(None, s1, s2)
     pos_a, pos_b, size = s.find_longest_match(0, len(s1), 0, len(s2))
     return s1[pos_a:pos_a+size]

overlap = get_overlap(ans, pred)
plus = ans.replace(get_overlap(ans, pred), "")
oo = pred.replace(get_overlap(ans, pred), "")

print len(overlap)
print len(plus)
print len(oo)

查找两个字符串的联系和非联系部分

2 个答案: