1、python对象3个属性：身份(id()获取)，类型(type()获取)，值

2、对象值的比较和对象身份的比较：前者就不说了，后者用is或is not，表示两个变量是否实质为同一个对象的引用。

3、检查类型

#!/usr/bin/env python

def displayNumType(num):
    print num, 'is',
    if isinstance(num, (int, long, float, complex)):
        print 'a number of type:', type(num).__name__
    else:
        print 'not a number at all!!'


import types
def displayNumType2(num):
    print num, 'is a number of type: ',
    if type(num) == types.IntType:
        print types.IntType
    elif type(num) == types.StringType:
        print types.StringType
    elif type(num) == types.FloatType:
        print types.FloatType
    elif type(num) == types.ComplexType:
        print types.ComplexType
    elif type(num) == types.LongType:
        print types.LongType
    else:
        print 'not a number at all!!'
        
        
displayNumType(-69)
displayNumType(9999999999999999999999L)
displayNumType(98.6)
displayNumType(-5.2+1.9j)
displayNumType('xxx')

print '==========================================='

displayNumType2(-69)
displayNumType2(9999999999999999999999L)
displayNumType2(98.6)
displayNumType2(-5.2+1.9j)
displayNumType2('xxx')