Special characters cannot be identified in helloworld example

[BruceQin2016]

I did a setup in vscode-playground and copied the code from helloworld.py to Servers folder.
Then i launched the server by press F5 in vscode-playground side and type this in helloworld.txt but nothing happened

It seems that special characters such as "." "/" "," cannot be identified.
How can i do?

[BruceQin2016]

Here is my code of hello_world.py

[alcarney]

It looks like the hello world example is missing trigger characters if you change the @server.feature decorator to something like

@server.feature(
    TEXT_DOCUMENT_COMPLETION,
    CompletionOptions(trigger_characters=["."]),
)

does that improve things?

[BruceQin2016]

yes, after i add it , it works fine