[Orgmode] how to "untag" subtree?

[Maxim Loginov]

hi all

I use tag inheritance, but sometimes I do not want that subtree has
one or more inherited tags. like this:

* Python                                              :python:
** TODO write script A
   A is written in python, so tag :python: is ok
*** TODO look how it is implemented in B
    B is not related to python and I do not want 
    to have tag :python: on this subtree!

is there any mechanism to untag subtree?

thanks
Maxim Loginov