python學習筆記-difflibf組件

　　difflib組件提供了一種在兩個序列之間進行比較的工具，比較兩個序列串中之間的差別類似於linux中diff命令。常用的功能有Diff類,ndiff函數,unified_diff函數,context_diff函數,HtmlDiff類,以及SequenceMatcher類。

　　Diff類以及ndiff：

　　Diff類和ndiff中兩個功能輸出的結果基本相似，用法稍有不同：　

#Differ使用
d =  difflib.Differ()
diff = d.compare(text1_lines, text2_lines)
#ndiff使用
diff = difflib.ndiff(text1_lines, text2_lines)

　　unified_diff，context_diff，HtmlDiff：

　　以上者三個函數控制比較結果的輸出格式。如果HtmlDiff類中make_file是的比較結果以html的源代碼輸出，unified_diff將相同串放在一起輸出。

#content_diff用法
diff = difflib.context_diff(text1_lines,text2_lines)
#unified_diff用法
diff = difflib.unified_diff(text1_lines,text2_lines)
#HtmlData用法：
diff = difflib.HtmlDiff()
diff.make_file(text1_lines,text2_lines)
#也可以
diff.make_table(text1_lines,text2_lines)

　　SequenceMatcher類：

　　可以手動設置忽略的字符，同時可以用於比較任意類型的序列。不過這個序列中的元素需要有對應的hash值

　　

import difflib
from difflib_data import *

s1 = [1,2,3,5,6,4]
s2 = [2,3,5,4,6,1]

print 'Initial data:'
print 's1 =', s1
print 's2 =', s2
print 's1==s2',s1==s2
print
matcher = difflib.SequenceMatcher(None,s1,s2)

for tag, i1, i2, j1, j2 in reversed(matcher.get_opcodes()):
    if tag == 'delete':
        print 'Remove %s from positions [%d:%d]'%(s1[i1:i2],i1,i2)
        del s1[i1:i2]
    elif tag == 'equal':
        print 'The sections [%d:%d] of s1 and [%d:%d] of s2 are the same' % \
              (i1, i2, j1, j2)

    elif tag == 'insert':
        print 'Insert %s from [%d:%d] of s2 into s1 at %d' % \
              (s2[j1:j2], j1, j2, i1)
        s1[i1:i2] = s2[j1:j2]

    elif tag == 'replace':
        print 'Replace %s from [%d:%d] of s1 with %s from [%d:%d] of s2' % (
            s1[i1:i2], i1, i2, s2[j1:j2], j1, j2)
        s1[i1:i2] = s2[j1:j2]

    print 's1 =', s1
    print 's2 =', s2
    print

print 's1 == s2:', s1 == s2