[Python] An installed python library is not being loaded in a docker container

I am trying to run a Python program in a docker container. The program uses the bcrypt library. It runs without problems outside of a docker container (using intellij ultimate), but it does not run properly in a docker container.

My Dockerfile installs bcrypt, as shown below:

FROM python:3.13-slim

WORKDIR /app
COPY webservice.py .
COPY f3login.py .
COPY dbaccess.py .

.
.
.
RUN pip3 install bcrypt
RUN pip3 install openai
RUN pip3 install langchain
RUN pip3 install langchain_openai
RUN pip3 install extra-streamlit-components
RUN pip3 install streamlit
RUN pip3 install streamlit-browser-engine
RUN pip3 install pymal


CMD ["python3","-m","streamlit","run","f3aichatter.py"]


Unfortunately, when I run my program, it runs without problems until I actually attempt to access the application. Then I get the following:

service | 2025-11-26 04:42:25.690 Uncaught app execution
service | Traceback (most recent call last):
service | File "/usr/local/lib/python3.13/site-packages/streamlit/runtime/scriptrunner/exec_code.py", line 129, in exec_func_with_error_handling
service | result = func()
service | File "/usr/local/lib/python3.13/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 669, in code_to_exec
service | exec(code, module.__dict__) # noqa: S102
service | ~~~~^^^^^^^^^^^^^^^^^^^^^^^
service | File "/app/f3aichatter.py", line 3, in <module>
service | from f3login import F3Login
service | File "/app/f3login.py", line 5, in <module>
service | import bcrypt
service | ModuleNotFoundError: No module named 'bcrypt'


This, of course, makes no sense. I am installing bcrypt and it looks like the python script is loading all the other libraries (f3login.py loads bcrypt last). The application should load bcrypt, but it isn't.

Can someone tell me why my application is not finding bcrypt?

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