You can repeat a test session or individual tests without leaving the Run tool window. The tests are performed again using the same run configuration as in the initial run.
Rerun a testing session
Press Ctrl+F5 or click the Rerun button on the toolbar of Test Runner tab .
In the Test Runner tab , right-click a test case node or a test and select Run <test_target>.
Rerun failed tests
In the Test Runner tab , click the Rerun Failed Tests button on the toolbar.
Rerunning tests automatically
PyCharm lets you rerun run/debug configuration of a test automatically, if the source code has been changed. To enable autotest-like runner facility, make sure that the Toggle auto-test button in the Run toolbar of the Test Runner tab is pressed.
Press the Toggle auto-test button on the Run toolbar of the Test Runner tab.
When one or several tests in your test suite failed, debugging can help you quickly inspect the failures, preview the problematic code lines in the editor, and fix them.
Open the project Settings (Ctrl+Alt+S). Go to Build, Execution, Deployment | Python Debugger and select the Drop into debugger on failed tests checkbox.
Open the test file in the editor. Right-click it and select the Debug <test name>.
PyCharm stops on every failed test and shows the reason for the failure. Inspect the Variables pane of the Debugger tool window to get more details about the problems.
on the toolbar of Test Runner tab . 
on the toolbar. 
in the Run toolbar of the Test Runner tab is pressed.
) in the gutter and terminate the debugging process.
