When a project is created, a corresponding project file is created on the computer, and tags, picture files, alarms, etc. are included in the file. What is the path of the perspective project?
No matter how much I search, I can't find the project file.
Incorrect (depending on what you call "picture files" (I'm assuming you're talking about Image Management images). These are all stored in the config.idb database and these are Gateway-scoped, not project-scoped.
All configuration-related files are stored under here (for Windows): C:\Program Files\Inductive Automation\Ignition\data
Perspective project files are stored under: .\projects\<ProjectName>\com.inductiveautomation.perspective\...
Perspective theme files, icons, and fonts are stored under: .\modules\com.inductiveautomation.perspective\...
The config.idb is stored under: .\db\...
You can get the data directory if you run this from the gateway scope (which includes from a Perspective session):
from com.inductiveautomation.ignition.gateway import IgnitionGateway
context = IgnitionGateway.get()
projectParentFolder = str(context.systemManager.dataDir.absoluteFile).replace('\\','/')