解包装SequenceMatcher循环结果

Question

在Python中解包SequenceMatcher循环的最佳方法是什么，以便可以方便地访问和处理值？

from difflib import *

orig = "1234567890"

commented = "123435456353453578901343154"

diff = SequenceMatcher(None, orig, commented)

match_id = []
for block in diff.get_matching_blocks():
    match_id.append(block)

print(match_id)

字符串整数表示汉字。

当前迭代代码存储匹配的结果如下所示：

match_id
[Match(a=0, b=0, size=4), Match(a=4, b=7, size=2), Match(a=6, b=16, size=4), Match(a=10, b=27, size=0)]

最后，我想用"{{"和"}}"来标记如下评论：

"1234{{354}}56{{3534535}}7890{{1343154}}"

这意味着，我对解压上述SequenceMatcher结果感兴趣，并对特定的b和size值进行了一些计算，以得到以下序列：

rslt = [[0+4,7],[7+2,16],[16+4,27]]

这是[b[i]+size[i],b[i+1]]的重复。

Answer 1

1.解包装SequenceMatcher结果以生成序列

您可以解压缩match_id，然后在表达式中使用列表理解。

a, b, size = zip(*match_id)
# a    = (0, 4,  6, 10)
# b    = (0, 7, 16, 27)
# size = (4, 2,  4,  0)

rslt = [[b[i] + size[i], b[i+1]] for i in range(len(match_id)-1)]
# rslt = [[4, 7], [9, 16], [20, 27]]

zip的引用，Python内置函数：https://docs.python.org/3/library/functions.html#zip

2.用"{{"和"}}"标记评论

您可以循环遍历rslt，然后很好地添加到目前为止的匹配项，并标记注释。

rslt_str = ""
prev_end = 0

for start, end in rslt:
    rslt_str += commented[prev_end:start]
    if start != end:
        rslt_str += "{{%s}}" % commented[start:end]
    prev_end = end
# rslt_str = "1234{{354}}56{{3534535}}7890{{1343154}}"

Answer 2

我会这样做：

from difflib import *

orig = "1234567890"
commented = "123435456353453578901343154"

diff = SequenceMatcher(None, orig, commented)

match_id = []
rslt_str = ""
for block in diff.get_matching_blocks():
    match_id.append(block)

temp = 0
for i, m in enumerate(match_id[:-1]):
    rslt_str += commented[temp:m.b + m.size] + "{{"
    rslt_str += commented[m.b + m.size: match_id[i+1].b] + "}}"
    temp = match_id[i+1].b

所以rslt_str == "1234{{354}}56{{3534535}}7890{{1343154}}"

Answer 3

你可以试试这个：

from difflib import *

orig = "1234567890"
commented = "123435456353453578901343154"
diff = SequenceMatcher(None, orig, commented)

a, b, size = zip(*diff.get_matching_blocks())

start = {x + y : '{{' for x, y in zip(b[:-1],size)}
end = dict.fromkeys(b[1:], '}}')
rslt = {**start, **end}

final_str = ''.join(rslt.get(ix,'') + n for ix, n in enumerate(commented)) + '}}'

print(final_str)

输出：

'1234{{354}}56{{3534535}}7890{{1343154}}'

解释

因为SequenceMatcher().matching_blocks()是可迭代的，所以您可以直接将它解压缩到变量中。

然后创建一个以开始索引作为键的字典，以value.

• Similarly，创建以结束索引作为键的字典，以value.

• Unpack创建}}，这是rslt.

中的两个字典。

然后通过将commented的字符作为默认值传递给dict.get和rslt dict中的索引，形成一个列表，在字符前面加上相应的大括号。最后加入到字符串中。