Python difflib：突出显示内联差异？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/774316/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Python difflib: highlighting differences inline?
提问by AnC
When comparing similar lines, I want to highlight the differences on the same line:
在比较相似的线条时，我想突出显示同一线条上的差异：
a) lorem ipsum dolor sit amet
b) lorem foo ipsum dolor amet
lorem <ins>foo</ins> ipsum dolor <del>sit</del> amet
While difflib.HtmlDiff appears to do this sort of inline highlighting, it produces very verbose markup.
虽然 difflib.HtmlDiff 似乎执行这种内联突出显示，但它会产生非常冗长的标记。
Unfortunately, I have not been able to find another class/method which does not operate on a line-by-line basis.
不幸的是，我无法找到另一个不能逐行运行的类/方法。
Am I missing anything? Any pointers would be appreciated!
我错过了什么吗？任何指针将不胜感激！
回答by tzot
For your simple example:
对于您的简单示例：
import difflib
def show_diff(seqm):
"""Unify operations between two compared strings
seqm is a difflib.SequenceMatcher instance whose a & b are strings"""
output= []
for opcode, a0, a1, b0, b1 in seqm.get_opcodes():
if opcode == 'equal':
output.append(seqm.a[a0:a1])
elif opcode == 'insert':
output.append("<ins>" + seqm.b[b0:b1] + "</ins>")
elif opcode == 'delete':
output.append("<del>" + seqm.a[a0:a1] + "</del>")
elif opcode == 'replace':
raise NotImplementedError, "what to do with 'replace' opcode?"
else:
raise RuntimeError, "unexpected opcode"
return ''.join(output)
>>> sm= difflib.SequenceMatcher(None, "lorem ipsum dolor sit amet", "lorem foo ipsum dolor amet")
>>> show_diff(sm)
'lorem<ins> foo</ins> ipsum dolor <del>sit </del>amet'
This works with strings. You should decide what to do with "replace" opcodes.
这适用于字符串。您应该决定如何处理“替换”操作码。
回答by orip
Here's an inline differ inspired by @tzot's answer above(also Python 3 compatible):
这是一个内联差异，灵感来自上面@tzot 的回答（也兼容 Python 3）：
def inline_diff(a, b):
import difflib
matcher = difflib.SequenceMatcher(None, a, b)
def process_tag(tag, i1, i2, j1, j2):
if tag == 'replace':
return '{' + matcher.a[i1:i2] + ' -> ' + matcher.b[j1:j2] + '}'
if tag == 'delete':
return '{- ' + matcher.a[i1:i2] + '}'
if tag == 'equal':
return matcher.a[i1:i2]
if tag == 'insert':
return '{+ ' + matcher.b[j1:j2] + '}'
assert False, "Unknown tag %r"%tag
return ''.join(process_tag(*t) for t in matcher.get_opcodes())
It's not perfect, for example, it would be nice to expand 'replace' opcodes to recognize the full word replaced instead of just the few different letters, but it's a good place to start.
它并不完美，例如，扩展“替换”操作码以识别替换的完整单词而不是几个不同的字母会很好，但这是一个很好的起点。
Sample output:
示例输出：
>>> a='Lorem ipsum dolor sit amet consectetur adipiscing'
>>> b='Lorem bananas ipsum cabbage sit amet adipiscing'
>>> print(inline_diff(a, b))
Lorem{+ bananas} ipsum {dolor -> cabbage} sit amet{- consectetur} adipiscing
回答by Adam
difflib.SequenceMatcherwill operate on single lines. You can use the "opcodes" to determine how to change the first line to make it the second line.
difflib.SequenceMatcher将在单行上运行。您可以使用“操作码”来确定如何更改第一行以使其成为第二行。
