python内置函数3-cmp()

Help on built-in function cmp in module __builtin__:  cmp(...)      cmp(x, y) -> integer      Return negative if x<y, zero if x==y, positive if x>y.  cmp(x, y)  Compare the two objects x and y and return an integer according to the outcome. The return value is negative if x < y, zero if x == y and strictly positive if x > y.  中文说明:比较两个对象x和y,如果x < y ,返回负数;x == y, 返回0;x > y,返回正数。  版本:该函数只有在python2中可用,而且在python2所有版本中都可用。但是在python3中该函数已经被删减掉。  >>> cmp(3,4)  -1  >>> cmp(56,34)  1  >>> cmp(a,a)  Traceback (most recent call last):    File "<stdin>", line 1, in <module>  NameError: name 'a' is not defined  >>> cmp('a','a')  0  >>> cmp('abc','cbd')  -1