1 '''
2 merge two configure files, basic file is aFile
3 insert the added content of bFile compare to aFile
4 for example, 'bbb' is added content
5 -----------------------------------------------------------
6 a file content | b file content | c merged file content
7 111 | 111 | 111
8 aaa | bbb | aaa
9 | | bbb
10 222 | 222 | 222
11 ------------------------------------------------------------
12 '''
13 def mergeFiles(aPath, bPath, cPath):
14
15 with open(aPath, 'r') as f:
16 aLines = f.readlines();
17 aLines = [ line.strip() + '\n' for line in aLines]
18
19 with open(bPath, 'r') as f:
20 bLines = f.readlines();
21 bLines = [ line.strip() + '\n' for line in bLines]
22
23 cLines = mergeSequences(aLines, bLines)
24
25 with open(cPath, 'w') as f:
26 for line in cLines:
27 f.write(line)
28
29 '''
30 merge the sequence
31 '''
32 def mergeSequences(aLines, bLines):
33 record = {}
34 lcs = findLCS(record, aLines, 0, bLines, 0)
35 currA = currB = 0
36 merged = []
37 for (line, aI, bI) in lcs:
38
39 # add deleted
40 if aI > currA:
41 merged.extend(aLines[currA:aI])
42 currA = aI + 1
43
44 # add added
45 if bI > currB:
46 merged.extend(bLines[currB:bI])
47 currB = bI + 1
48
49 # add common
50 merged.append(line)
51
52 if currA < len(aLines):
53 merged.extend(aLines[currA:])
54 if currB < len(bLines):
55 merged.extend(bLines[currB:])
56
57 return merged
58
59 '''
60 find Longest common subsequence
61 return list of (line, x, y)
62 line is common line, x is the index in aLines, y is the index in bLines
63 TODO: eliminate recursive invoke, use dynamic algorithm
64 '''
65 def findLCS(record, aLines, aStart, bLines, bStart):
66
67 key = lcsKey(aStart, bStart)
68 if record.has_key(key):
69 return record[key]
70
71 aL = aLines[aStart:]
72 bL = bLines[bStart:]
73 if len(aL) > 0 and len(bL) > 0:
74 if aL[0] == bL[0]:
75 lsc = [(aL[0], aStart, bStart)]
76 lsc.extend(findLCS(record, aLines, aStart + 1, bLines, bStart + 1))
77 record[key] = lsc
78 return lsc
79 else:
80 aLsc = findLCS(record, aLines, aStart, bLines, bStart + 1)
81 bLsc = findLCS(record, aLines, aStart + 1, bLines, bStart)
82
83 if len(aLsc) > len(bLsc):
84 record[key] = aLsc
85 return aLsc
86 else:
87 record[key] = bLsc
88 return bLsc
89 else:
90 return []
91
92 Code
