PyCharm Community lets you compare the following via context menu commands:
- directories
- a class or class member with another class or class member
- a local file with its versions in Local History
- a local file with its current revision in your version control repository
- any two revisions of the same file
- any local file with the file currently opened in the Editor
- any two local files with each other: text or binary
- active Editor with the clipboard contents
- any text sources you paste into a blank diff window
You can configure the Diff tool in the Settings/Preferences dialog &shortcut:ShowSettings; under Tools | Diff & Merge.