I am playing with IDLE. But it seems that intellisense in IDLE is a bit slow. When we type time. I need to wait a second or more for the intellisense to appear. What is the reason for this? I have heard that IDLE is developed in Python itself and that Python is a bit slower than other languages (slower but not notably so).
Now, is the slowness of Python the reason?
You did not specify the exact release you are using, but currently (Since about Sept 2014), IDLE makes changing the popup delay easy.  Select Options and Configure Extensions if you see that choice.  Otherwise select Configure IDLE and then the Extensions tab (since Fall 2015).  In either case, select AutoComplete and change the popupwait.  I happen to have reset to to 0 for myself.  I think 2 seconds is too long, but changing the default is problematical.
Intellisence in IDLE is slow. Is the slowness of python the reason?