pytest Tutorial 1 - Beginner

math_func.py

def add(x,y):
   return x+y

def product(x,y)
   return x*y

test_math_func.py

from math_func import add, subtract
import pytest
import sys

# @pytest.mark.skip(reason="Do not run number add test")
# @pytest.mark.skipif(sys.version_info < (3, 3), reason="Do not run number add test") 
@pytest.mark.number
def test_add():
   assert add(3,4) == 7
   print(f'Inside test_add: {assert add(3,4)}')

@pytest.mark.parameterize('arg1, arg2, result',
[
(7, 3, 10),
('Hello', ' World', 'Hello World')
(5.5, 4.5, 10)
]
)
def test_add_parameterize(arg1, arg2, result):
   assert add(arg1, arg2) == result

@pytest.mark.number
def test_product():
   assert add(3,4) == 12
 
@pytest.mark.strings
def test_add_strings():
   assert add(3,4) == 7
   result add('Hello', ' World')
   assert result == 'Hello World'
   assert 'Hello' in result
   assert type(result) is str 

@pytest.mark.strings
def test_product_strings():
   assert product('Hello', 3) == 'HelloHelloHello'

How to run
pytest test_match_func.py
pytest test_match_func.py -v

pytest test_match_func.py::test_add

(-k Expression)
pytest -v -k "add"  # runs tests with "add" string, run both test_add & test_add_strings
pytest -v -k "add or string" # runs all 3
pytest -v -k "add and string"  # runs test_add_strings alone

(-m, --markers)
pytest -v -m number # run those marked as number
pytest -v -m strings  # run those marked as strings

(-x, --exitfirst)

pytest -v -x  # If any first failure, it totally exits and does not execute following tests

pytest -v -x --tb=no  # It won't show error stack trace

pytest -v --maxfail=2

pytest -v -s  # -s option will output any print lines

pytest -v -q  # quite mode, will not print how many test passed

pytest Tutorial 2 -Fixtures (check the other blog)