为何修改Python文件后需重启Odoo？解释型语言下的疑问

Great question—this is a super common point of confusion for Odoo developers, especially since Python is billed as an interpreted language. Let’s break down the key reasons behind this behavior in plain terms:

1. Why you can install new modules without restarting #

When you drop a new module into the addons folder and click "Update Apps List" in Odoo, the server only scans for module manifest files (__manifest__.py). This scan reads basic metadata like the module name, dependencies, and description—it doesn’t load any of the module’s actual Python code into memory yet. The Python code only gets loaded when you install the module, a one-time initialization step that works smoothly within the running server’s context.

2. Why modified Python files require a restart #

Once Odoo starts up (or finishes installing a module), it loads all the module’s Python code into the server’s memory and compiles it into bytecode. Here’s why this blocks hot-updates:

• Python’s runtime quirk: Even though Python is interpreted, once code is loaded into memory, the interpreter sticks with that in-memory version forever. It doesn’t automatically watch the original .py files for changes or reload them in the background.
• Odoo’s static initialization: Critical parts of Odoo—like model definitions, controller routes, permission rules, and core business logic—are registered during the initial code load. These registrations live as fixed structures in the server’s memory. For example, if you add a new field to a model or tweak a method, the in-memory model class won’t update on its own; the server will keep using the old version it loaded at startup.
• Upgrade doesn’t equal reload: The "Upgrade" button in Odoo only handles updates to data and views (like XML layouts, database records, or module dependencies). It can’t trigger a reload of Python code, since that would require resetting the server’s entire in-memory state—something that can’t be done safely without a full restart.

Is there any way to skip restarting? #

In development environments, you can use the --dev reload flag when starting Odoo. This enables auto-restart whenever it detects changes to Python files, saving you from manually restarting each time. However, this is strictly for development—never use it in production, as it can cause inconsistent states or memory leaks.

内容的提问来源于stack exchange，提问作者Vivek