No module named pycuda

[JiangWeiHn]

Environment (please complete the following information):

• OS: ubuntu 20.04
• CUDA version: 11.1
• CUDA driver version: 470.57.02
• PyCUDA version: 2021.1
• Python version: 3.9

Additional context
when i run pip install pycuda==2021.1,i got :
Requirement already satisfied: pycuda==2021.1 in ./anaconda3/lib/python3.8/site-packages (2021.1)
Requirement already satisfied: appdirs>=1.4.0 in ./anaconda3/lib/python3.8/site-packages (from pycuda==2021.1) (1.4.4)
Requirement already satisfied: mako in ./anaconda3/lib/python3.8/site-packages (from pycuda==2021.1) (1.1.6)
Requirement already satisfied: pytools>=2011.2 in ./anaconda3/lib/python3.8/site-packages (from pycuda==2021.1) (2021.2.9)
Requirement already satisfied: numpy>=1.6.0 in ./.local/lib/python3.8/site-packages (from pytools>=2011.2->pycuda==2021.1) (1.19.5)
Requirement already satisfied: MarkupSafe>=0.9.2 in ./anaconda3/lib/python3.8/site-packages (from mako->pycuda==2021.1) (1.1.1)

when i import pycuda, i got:

Traceback (most recent call last):
File "", line 1, in
ModuleNotFoundError: No module named 'pycuda'
how can i fix this bug?