获取已更改的行号

Question

给定两个文本文件A,B,什么是一种简单的方法来获取A中不存在B中的行数？我看到有difflib,但没有看到用于检索行号的接口

Answer 1

difflib可以满足您的需求.假设:

A.TXT

this 
is 
a 
bunch 
of 
lines

b.txt

this 
is 
a 
different
bunch 
of 
other
lines

像这样的代码:

import difflib

fileA = open("a.txt", "rt").readlines()
fileB = open("b.txt", "rt").readlines()

d = difflib.Differ()
diffs = d.compare(fileA, fileB)
lineNum = 0

for line in diffs:
   # split off the code
   code = line[:2]
   # if the  line is in both files or just b, increment the line number.
   if code in ("  ", "+ "):
      lineNum += 1
   # if this line is only in b, print the line number and the text on the line
   if code == "+ ":
      print "%d: %s" % (lineNum, line[2:].strip())

给出如下输出:

bgporter@varese ~/temp:python diffy.py 
4: different
7: other

您还需要查看difflib代码"? "并查看您希望如何处理该代码.

(另外,在实际代码中,您希望使用上下文管理器来确保文件被关闭等等)