有没有办法忽略 ndiff 库中的空行并只打印 + 和行号？ PYTHON

Question

伙计们，这是我的代码：

import io
import difflib
import re

with io.open('textest.txt', mode="r", encoding="utf_8_sig") as file:
    lines1 = file.readlines()
    

with io.open('minitext.txt', mode="r", encoding="utf_8_sig") as file:
    lines2 = file.readlines()

def prefilter(line):
    return re.sub("\s+"," ",line.strip())


for d in difflib.ndiff([prefilter(x) for x in lines1],[prefilter(x) for x in lines2]):
    print(d)

textest.txt 是完整的歌曲，minitext.txt 只是其中的一部分。输出是这样的（我知道，这是一首贾斯汀比伯的歌，这只是一个例子）

+ somethin' I don't wanna hold back
- For all the times that you rained on my parade
- And all the clubs you get in using my name
- You think you broke my heart, oh, girl, for goodness' sake
- You think I'm crying on my own, well, I ain't
- And I didn't wanna write a song
- 'Cause I didn't want anyone thinkin' I still care, I don't, but
- You still hit my phone up
- And baby, I'll be movin' on
- And I think you should be somethin' I don't wanna hold back
  Maybe you should know that
  My mama don't like you and she likes everyone
  And I never like to admit that I was wrong
  And I've been so caught up in my job
  Didn't see what's going on, but now I know
+
+
+
  I'm better sleeping on my own
+ 'Cause if you like the wa
- 'Cause if you like the way you look that much
- Oh, baby, you should go and love yourself
- And if you think that I'm still holdin' on to somethin'

问题是：我只想打印 +（lines2 上的不同行，即 minitext.txt），以及不同的行号。我还想忽略完全空行，所以输出就像：

• 有些事情我不想阻止（minitext.txt 中的行数）
• '因为如果你喜欢 wa（minitext.txt 中的行数）

或类似的东西。有什么办法可以做到吗？

Answer 1

import difflib


# over write Differ class (difflib.ndiff work with compare function that exist in this class)
class Differ(difflib.Differ):
    # this function used for + tag
    def _dump(self, tag, x, lo, hi):
        """Generate comparison results for a same-tagged range."""
        for i in range(lo, hi):
            # only yield if tag == "+"
            if tag == '+':
                # if second list not empty yield result
                if x[i] != "":
                    # change format (item of second list string, i==index (number line start from 0))
                    yield '%s(%s)' % (x[i], i)


# example of two list of string
a = ["first", "second", "three", "four"]
b = ["number_one", "second", "number_three", "four"]

differ_object = Differ()
result = differ_object.compare(a, b)
for _ in result:
    print(_)
# result
"""
number_one(0)
number_three(2)
"""