pytest_ executed by tag

pytest Import 
@ pytest.mark.webtest 
DEF test_send_http (): 
    Pass 

@ pytest.mark.apptest 
DEF test_devide (): 
    Pass 

@ pytest.mark.android 
DEF test_search (): 
    Pass 

@ pytest.mark.ios 
DEF test_add (): 
    Pass 

test_plus DEF (): 
    Pass 

-m is a marker 
-s display print an internal

pytest -s test_mark.py -m 'not ios' execution flag is not equal to the ios

pytest -s test_mark.py -m ios only the execution flag == ios

pytest -s test_mark.py -m = ios only the execution flag == ios