Exceptions and error codes

When creating pages with PyScript, you may encounter exceptions. Each handled exception will contain a specific code which will give you more information about it. This reference guide contains the error codes you might find and a description of each of them.

User Errors

Error code	Description	Recommendation
PY1000	Invalid configuration supplied	Confirm that your py-config tag is using a valid TOML or JSON syntax and is using the correct configuration type.
PY1001	Unable to install package(s)	Confirm that the package contains a pure Python 3 wheel or the name of the package is correct.
PY2000	Invalid plugin file extension	Only .js and .py files can be used when loading user plugins. Please confirm your path contains the file extension.
PY2001	Plugin doesn’t contain a default export	Please add export default to the main plugin class.
PY9000	Top level await is deprecated	Create a coroutine with your code and schedule it with asyncio.ensure_future or similar

Fetch Errors

These error codes are related to any exception raised when trying to fetch a resource. If, while trying to fetch a resource, we encounter a status code that is not 200, the error code will contain the HTTP status code and the PY0 prefix. For example, if we encounter a 404 error, the error code will be P02404.

Error Code	Description
PY0001	Generic fetch error, failed to fetch page from the server
PY0002	Name supplied when trying to fetch resource is invalid
PY0401	You are not authorized to access this resource.
PY0403	You are not allowed to access this resource.
PY0404	The page you are trying to fetch does not exist.
PY0500	The server encountered an internal error.
PY0503	The server is currently unavailable.

PY1001

Pyscript cannot install the package(s) you specified in your py-config tag. This can happen for a few reasons:

• The package does not exist

• The package does not contain a pure Python 3 wheel

• An error occurred while trying to install the package

An error banner should appear on your page with the error code and a description of the error or a traceback. You can also check the developer console for more information.

PY2001

Javascript plugins must export a default class. This is required for PyScript to be able to load the plugin. Please add export default to the main plugin class. For example:

export default class HelloWorldPlugin {
     afterStartup(runtime) {
        console.log("Hello World from the plugin!");
     }