import overwrites __name__

[Marco]

Hi,

There happened something that I do not understand. Actually I don't even 
know how it can be possible.

I import a module and then the name space of the importing module seems do 
be overwritten.

my_name = __name__
print my_name
print len(dir())
from x import y as z
print __name__
print len(dir())
print my_name

->
__main__
119
x
117
unhandled NameError "name 'my_name' is not defined"

The module x is from me, and I am not aware of doing anything cruel there. 
What evil thing can be done in its sub module that can result in that 
strange thing?

br
Marco