difflib内置模块_文本对比和文件对比

1. 什么是difflib? 用来做什么?

difflib为python的标准库模块，无需安装。作用时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. difflib符号理解

文本对比：

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)

# 实现linux里面的diff命令的功能
d = difflib.Differ()
print(''.join(list(d.compare(text1,text2))))

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

用HTML来表示文本之间的差异：

文件对比：

import difflib

filename1 = '/etc/passwd'
filename2 = '/tmp/passwd'

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('doc/passwdDiff.html','w') as f:
    f.write(htmlContent)