Code hinter causes incorrect entry

This case found when typing in a _variables.py_ example.

Up to here, all entries and behavior is fine (note cursor position and code hint):

And here, one ")" character later, still fine (though I don't see how try/except is a good suggestion)

But then upon hitting enter key, that "a)" is replaced with the hinted block - not at all what user expects at that moment.

在 variables.py 範例中輸入內容以重現此問題，並按照螢幕截圖中顯示的游標和程式碼提示狀態進行操作。檢查在右括號後按下 Enter 時會發生什麼；當輸入的「a)」沒有被建議的區塊意外取代時，即表示完成。

由索引模型根據 Issue 內容生成。