返回程序运行中当前行

"""This provides a lineno() function to make it easy to grab the line
number that we're on.

"""

import inspect

def lineno():
    """Returns the current line number in our program."""
    return inspect.currentframe().f_back.f_lineno

if __name__ == '__main__':
    print "hello, this is line number", lineno()
    print 
    print 
    print "and this is line", lineno()