ModuleNotFoundError: No module named 'Cryptodome'

i have succesfully installed pycryptodomex==3.6.4.but i am getting this wierd error ModuleNotFoundError: No module named 'Cryptodome.
system information
uname = linux
uname -r = 4.14.126-1.2.0+g6b774ee
uname -v = #1 SMP PREEMPT Mon Jan 20 14:03:55 UTC 2020
uname -v = armv7l

Start by reproducing the Cryptodome import failure in the reported Linux ARM environment with pycryptodomex==3.6.4 installed. The issue names no repository files or tests, so first locate the plugin entry point that imports Cryptodome and verify that the dependency is available to the same Python environment; done means the plugin loads without ModuleNotFoundError.

Written by the indexing model from the issue text.