Python modulenotfound error - Is there a "pip" alternative way to install python modules

Question

I am trying to run a program (obviously written in python) and it requires some python modules. One of the missed modules is aiomultiprocess. I tried installing it with pip install aiomultiprocess pip3 install aiomultiprocess python3.7 -m pip install aiomultiprocess but they all come back with the same error message:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/local/lib/python3.7/site-packages/setuptools/__init__.py", line 19, in <module>
    from setuptools.dist import Distribution
  File "/usr/local/lib/python3.7/site-packages/setuptools/dist.py", line 34, in <module>
    from setuptools import windows_support
  File "/usr/local/lib/python3.7/site-packages/setuptools/windows_support.py", line 2, in <module>
    import ctypes
  File "/usr/local/lib/python3.7/ctypes/__init__.py", line 10, in <module>
    from _ctypes import Union, Structure, Array
  File "/usr/local/lib/python3.7/_ctypes.py", line 5, in <module>
    import ffi
ModuleNotFoundError: No module named 'ffi'

No ffi module?! Let's get it! I looked it up and figured it's a foreign library that come, in the case of python, as 2 forms: CFFI & LibFFI, but "ffi" doesn't exist for python. I installed cffi libffi and added them to this path /usr/local/lib/python3.7/site-packages/, but it changed nothing.

So my question is there another way to install python modules without the need of pip??!