@pytest.yield_fixture(scope=u'module', autouse=True)
def ctx():
 builtins.__xonsh_shell__ = Shell({u'PATH': []})
 (yield)
 del builtins.__xonsh_shell__

@ pytest . yield_fixture ( scope = u'module' , autouse = True ) def ctx ( ) : builtins . __xonsh_shell__ = Shell ( { u'PATH' : [ ] } ) ( yield ) del builtins . __xonsh_shell__
create a global shell instance to use in all the test .