How to correctly update taichi?

I run

sudo pip3 install --upgrade taichi

And terminal is downloading taichi 0.6.35 but when I run

[Taichi] mode=release
[Taichi] preparing sandbox at /tmp/taichi-rowlx4kg
[Taichi] version 0.6.33, llvm 10.0.0, commit c1df4047, linux, python 3.8.2

it shows that I am still using the version of taichi 0.6.33.
I then use

ti update

I got

AttributeError: module 'taichi_core' has no attribute 'update' ".

What’s the problem?

OMG, I’m being silly,no sudo…