how to make my log more flexible?

[Frank Zheng]

Hi, all:
    I have a GUI program , And i add log in my program to know what happened
at run time.

for example:
def fun(log):
...#do some sth
log.write('do some sth')

at run time:
fun(open('mylogfile.log','w'))

Now, I want do some unit test first, my question is what param to be passed
to 'fun' can make 'log.write(...)' work as 'print'?

Thanks in advance!


Frank