python - Check if expection is raised with pytest -

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• how assert exception gets raised in pytest? 5 answers

being quite new exception test handling wondering how check if assertion raised.

a.py

class someerror(exception):     pass  class someclass(object):     def __init__(self):         ...         raise someerror         ... 

test_a.py

from a.a import someclass  def test_some_exception_raised():     ? 

what assertion should there check if someerror raised? using pytest.

in order write assertions raised exceptions, can use pytest.raises context manager this:

a.py

class someerror(exception):     pass  class someclass(object):     def __init__(self):         ...         raise someerror("some errror message")         ... 

test_a.py

from .a import someclass, someerror import pytest  def test_some_exception_raised():     pytest.raises(someerror) excinfo:            obj = someclass()        assert 'some errror message' in str(excinfo.value) 

for more exception assertions, click here