python之difflib模块文本对比

1. 什么是difflib? 用来做什么?
difflib为python的标准库模块，无需安装。
作用是对比文本之间的差异。
并且支持输出可读性比较强的HTML文档，与Linux下的diff命令相似。
在版本控制方面非常有用。

2. 符号理解
符号    含义
'-'     包含在第一个系列行中，但不包含第二个。
'+'     包含在第二个系列行中，但不包含第一个。
' '     两个系列行一致
'?'     存在增量差异
'^'     存在差异字符

text1 = '''  1. Beautiful is better than ugly.
       2. Explicit is better than implicit.
       3. Simple is better than complex.
       4. Complex is better than complicated.
		'''
text2 = '''  1. Beautiful is better than ugly.
       3.   Simple is better than complex.
       4. Complicated is better than complex.
       5. Flat is better than nested.
     '''

"""
import difflib
text1 = '''  1. Beautiful is better than ugly.
       2. Explicit is better than implicit.
       3. Simple is better than complex.
       4. Complex is better than complicated.
		'''.splitlines(keepends=True)
text2 = '''  1. Beautiful is better than ugly.
       3.   Simple is better than complex.
       4. Complicated is better than complex.
       5. Flat is better than nested.
     '''.splitlines(keepends=True)

# d = difflib.Differ()
# print(''.join(list(d.compare(text1,text2))))

d = difflib.HtmlDiff()
htmlContent = d.make_file(text1,text2)
# print(htmlContent)
with open('diff.html','w') as f:
    f.write(htmlContent)

linux文件之时间对比

import difflib
filename1 = '/tmp/passwd'
filename2 = '/tmp/passwd1'

with open(filename1) as f1,open(filename2) as f2:
    content1 = f1.read().splitlines(keepends=True)
    content2 = f2.read().splitlines(keepends=True)

d = difflib.HtmlDiff()
htmlcontent = d.make_file(content1,content2)
with open('passwdDiff.html','w') as f:
    f.write(htmlcontent)