简单比较是用内置函数 cmp() 来比较两个字符串:

Python 2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bit (Intel)] on
win32
Type "help", "copyright", "credits" or "license" for more information.
>>> a = "abc"
>>> b = "abc"
>>> cmp(a, b)
0
>>> c = "def"
>>> cmp(a,c)
-1
>>>

>
>>> import re
>>> m = re.search('multi', 'A mUltiCased string', re.IGNORECASE)
>>> bool(m)
True

在比较前把2个字符串转换成同样大写，用upper()方法，或小写,lower()
>>> s = 'A mUltiCased string'.lower()
>>> s
'a multicased string'
>>> s.find('multi')
2

使用python库difflib可以实现两个字符串的比较，找到相同的部分

python diff字符串比较模块