Students of the TU-Dresden can use the professional version of PyCharm (and most of the JetBrains products) for free for educational use. Go to Jetbrains-Students and fill out the form, note that you have to use your university email address (@tu-dresden.de, @msx.tu-dresden.de, @mailbox.tu-dresden.de). You will receive your license key via email there.
This usually means that the project root is not the same as the source-root. To test this, try importing from "src.[filename]" or "[folder_name].src.[filename]". Note that this will still prevent the script from running correctly on the brick, so now we have to make the old import-statement work.
Open PyCharm (…) and your project
Go to "Project: [name]>Project Structure"
Navigate to the src folder of your project and select it.
Press "Sources" (blue folder) to mark the selected src-folder as a sources-folder.
Press Apply and OK, the modules should now also be found locally and offer correct auto-completion (might take some seconds or restarting PyCharm to update)
Microsoft offers its IDE not only for Windows, but also Linux and Mac operating systems. You can download the software directly from their website.
Even if VSCode is not an IDE by default it is a good alternative.
Be aware it can be complicated to configure e.g. execution of unit-test using VSCode or do other things an IDE can do natively.
When working with EV3, VSCode offers to download specific python environments and/or images.
DO NOT DOWNLOAD THEM, USE OUR IMAGE AND VERSION 1 OF THE ev3dev-python BINDINGS!