pytest testing framework editor this can be seen in the following picture where green arrow has been added at line this is the 'run testbuttonthe developer can click on the green arrow to run the test they will then be presented with the run menu that is preconfigured to use pytest for youif the developer now selects the run optionthis will use the pytest runner to execute the test and collect information about what happened and present it in pytest output view at the bottom of the idehere you can see tree in the left-hand panel that currently holds the one test defined in the test_calculator py file this tree shows whether tests have passed or failed in this case we have green tick showing that the test passed to the right of this tree is the main output panel which shows the results of running the tests in this case it shows that pytest ran only one test and that this was the test_add_one test which was defined in test_calculator py and that test passed if you now change the assertion in the test to check to see that the result is the test will fail when runthe ide display will update accordingly the tree in the left-hand pane now shows the test as failed while the right-hand pane provides detailed information about the test that failed including where in the test the failed assertion was defined this is very helpful when trying to debug test failures