Hover the mouse pointer over a warning, error stripe or just some section on the scroll bar outside of the scroll box. PyCharm shows the source code fragment annotated with the warning/error messages.
This helps viewing the context a marker applies to, and the source code outside of the editor visible area.
This behavior is enabled by default.
To toggle the lens mode
- Do one of the following:
Open the Appearance page of the Settings dialog.
Right-click the code analysis marker on top of the current editor.
Select or clear the checkbox Show code lens on scrollbar hover.