举例讲解Python中的身份运算符的使用方法

Python身份运算符
身份运算符用于比较两个对象的存储单元

以下实例演示了Python所有身份运算符的操作：

    #!/usr/bin/python

    a = 20
    b = 20

    if ( a is b ):
      print "Line 1 - a and b have same identity"
    else:
      print "Line 1 - a and b do not have same identity"

    if ( id(a) == id(b) ):
      print "Line 2 - a and b have same identity"
    else:
      print "Line 2 - a and b do not have same identity"

    b = 30
    if ( a is b ):
      print "Line 3 - a and b have same identity"
    else:
      print "Line 3 - a and b do not have same identity"

    if ( a is not b ):
      print "Line 4 - a and b do not have same identity"
    else:
      print "Line 4 - a and b have same identity"

以上实例输出结果：

    Line 1 - a and b have same identity
    Line 2 - a and b have same identity
    Line 3 - a and b do not have same identity
    Line 4 - a and b do not have same identity