ModuleNotFoundError: No module named in a docker compose build

When I issue docker-compose up, I’m met with modulenotfound for flask-simpleldap. When I type the below in the env path, I see it’s installed.

(env) [email protected]:/home/administrator/app/flask# pip install flask-simpleldap
Requirement already satisfied: flask-simpleldap in ./env/lib/python3.6/site-packages (1.4.0)
Requirement already satisfied: python-ldap>=3.0.0 in ./env/lib/python3.6/site-packages (from flask-simpleldap) (3.2.0)
Requirement already satisfied: Flask>=0.12.4 in ./env/lib/python3.6/site-packages (from flask-simpleldap) (1.1.1)
Requirement already satisfied: pyasn1>=0.3.7 in ./env/lib/python3.6/site-packages (from python-ldap>=3.0.0->flask-simpleldap) (0.4.6)

I’ve removed all traces of python2.7 and rebuilt my docker instance with pip3 and python3 resources but am still having this issue.

flask    | *** Operational MODE: preforking+threaded ***
flask    | Traceback (most recent call last):
flask    |   File "", line 1, in <module>
flask    |     from app import app
flask    |   File "./app/", line 5, in <module>
flask    |     from app import views
flask    |   File "./app/", line 2, in <module>
flask    |     from flask_simpleldap import LDAP
flask    | ModuleNotFoundError: No module named 'flask_simpleldap'
flask    | unable to load app 0 (mountpoint='') (callable not found or import error)
flask    | *** no app loaded. going in full dynamic mode ***
flask    | uWSGI running as root, you can use --uid/--gid/--chroot options
flask    | *** WARNING: you are running uWSGI as root !!! (use the --uid flag) ***
flask    | *** uWSGI is running in multiple interpreter mode ***

Docker file:

# Use the Python3.7.2 image
FROM python:3.6

# Set the working directory to /app

# Copy the current directory contents into the container at /app 
ADD . /app

# Install the dependencies
RUN pip3 install -r requirements.txt

# run the command to start uWSGI
CMD ["uwsgi", "app.ini"]

Source: StackOverflow