In order to mark strings as “translatable” in Flask via Flask-WTF, you need to apply a special syntax.

This means, e.g. in a Jinja template a string like Conference has to be transformed into {{ _('Conference') }}.

This is a very tedious work, so I created a shortcut for it.

Add the following lines to your keybindings.json:

"key": "ctrl+shift+alt+0",
"command": "editor.action.insertSnippet",
"when": "editorHasSelection || editorHasMultipleSelections",
"args": {
    "snippet": "{{ _('${TM_SELECTED_TEXT}') }}"
}

I used “ctrl+shift+alt+0” as on keyboard with a German layout the closing curly brace is on the same key as the 0.

via https://stackoverflow.com/a/53545200/672833