python中for和if else的使用

In [8]: a = set(‘abcd‘)

In [9]: b = set(‘ef‘)

In [10]: def match(x,y):
   ....:     for i in x:
   ....:         for j in y:
   ....:             if i==j:
   ....:                 break
   ....:         else:
   ....:             return False
   ....:     return True
   ....: 

In [11]: match(a,b)
Out[11]: False

In [12]: match(a,a)
Out[12]: True

In [13]: match(a,set(‘ab‘))
Out[13]: False

In [14]: match(a,set(‘opqrsa‘))
Out[14]: False

In [15]: match(b,b)
Out[15]: True