Help with pyinstaller "No module named"

[snippsat]

It work when i test,i use virtual environment always when troubleshoot Pyinstaller.

# Make 
G:\div_code
λ python -m venv router_env

# Cd in
G:\div_code
λ cd router_env\

# Activate
G:\div_code\router_env
λ G:\div_code\router_env\Scripts\activate.bat

# Install
(router_env) G:\div_code\router_env
λ pip install pyinstaller RouterOS-api
.....
Installing collected packages: pywin32-ctypes, altgraph, six, pyinstaller-hooks-contrib, pefile, RouterOS-api, pyinstaller
Successfully installed RouterOS-api-0.17.0 altgraph-0.17.3 pefile-2023.2.7 pyinstaller-5.12.0
pyinstaller-hooks-contrib-2023.3 pywin32-ctypes-0.2.0 six-1.16.0

Test code:

# router.py
import routeros_api

connection = routeros_api.RouterOsApiPool('IP', username='admin', password='')
print(connection.username)
input('Press Enter to exit')

Build:

(router_env) G:\div_code\router_env
λ pyinstaller --onefile route.py
500 INFO: PyInstaller: 5.12.0
500 INFO: Python: 3.11.3
572 INFO: Platform: Windows-10-10.0.19045-SP0
.....
16020 INFO: Building EXE from EXE-00.toc completed successfully.

When run router.exe it print admin,so it work and find module routeros_api,
if not i would have gotten same error message as you get.