python 3.x - ImportError: No module named 'decouple' while deploying on Heroku

Question

I was trying to deploy my django project on heroku from heroku cli. So I created an app and then I ran git push heroku master from the project directory. Then I got the errors:

remote: -----> $ python manage.py collectstatic --noinput 
remote:      Traceback (most recent call last): 
remote:          File "manage.py", line 15, in <module> 
remote:            execute_from_command_line(sys.argv) 
remote:          File "/app/.heroku/python/lib/python3.5/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line 
remote:            utility.execute() 
remote:          File "/app/.heroku/python/lib/python3.5/site-packages/django/core/management/__init__.py", line 317, in execute 
remote:            settings.INSTALLED_APPS 
remote:          File "/app/.heroku/python/lib/python3.5/site-packages/django/conf/__init__.py", line 56, in __getattr__ 
remote:            self._setup(name) 
remote:   File "/app/.heroku/python/lib/python3.5/site-packages/django/conf/__init__.py", line 43, in _setup remote:            self._wrapped = Settings(settings_module) 
remote:          File "/app/.heroku/python/lib/python3.5/site-packages/django/conf/__init__.py", line 106, in __init__ 
remote:            mod = importlib.import_module(self.SETTINGS_MODULE) 
remote:          File "/app/.heroku/python/lib/python3.5/importlib/__init__.py", line 126, in import_module 
remote:            return _bootstrap._gcd_import(name[level:], package, level) 
remote:          File "<frozen importlib._bootstrap>", line 986, in _gcd_import 
remote: File "<frozen importlib._bootstrap>", line 969, in _find_and_load 
remote:          File "<frozen importlib._bootstrap>", line 958, in
_find_and_load_unlocked 
remote:          File "<frozen importlib._bootstrap>", line 673, in _load_unlocked 
remote:          File "<frozen importlib._bootstrap_external>", line 665, in exec_module 
remote:          File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed 
remote:          File "/tmp/build_93c58c906371cd0110470b6bb3ccecc1/funderpreneur/settings.py", line 15, in <module> 
remote:            from decouple import Csv, config 
remote:        ImportError: No module named 'decouple' 
remote:  
remote:  !     Error while running '$ python manage.py collectstatic --noinput'. 
remote:        See traceback above for details. 
remote:  
remote:        You may need to update application code to resolve this error. 
remote:        Or, you can disable collectstatic for this application: remote:  
remote:           $ heroku config:set DISABLE_COLLECTSTATIC=1 
remote:  
remote:        https://devcenter.heroku.com/articles/django-assets 
remote:  !     Push rejected, failed to compile Python app. 
remote:  
remote:  !     Push failed

So as it is mentioned, I ran heroku config:set DISABLE_COLLECTSTATIC=1. Then the codes were pushed in the repository. Then I ran heroku run python3 manage.py migrate. But still I got the same error saying:

File "/app/funderpreneur/settings.py", line 15, in

from decouple import Csv, config ImportError: No module named 'decouple'

But I have python-decouple installed locally for both python 2 and 3. And also the whole project is running on django version 2 and python version 3.5.2. But in the runtime.txt I have set python-3.6.4. I have requirements.txt where decouple is already there.

In my settings.py I had

import django_heroku
django_heroku.settings(locals())

But I was getting errors so I commented them. Still getting error.

What is wrong or what am I doing wrong?

Edit

My requirements.txt:

dj-database-url
django
gunicorn
psycopg2
whitenoise
dj-static
Unipath
python-decouple
Pillow
Markdown
bleach
python-decouple
django-material
raven
django-debug-toolbar
django-tables2
django-phonenumber-field
django-guardian
django-notifications-hq
djangorestframework
matplotlib
numpy
seaborn
pandas
django-heroku

And the strucutre is:

.
├── core
│?? ├── admin.py
│?? ├── apps.py
│?? ├── __init__.py
│?? ├── migrations
│?? │?? ├── __init__.py
│?? │?? └── __pycache__
│?? │??     └── __init__.cpython-35.pyc
│?? ├── models.py
│?? ├── __pycache__
│?? │?? ├── admin.cpython-35.pyc
│?? │?? ├── __init__.cpython-35.pyc
│?? │?? ├── models.cpython-35.pyc
│?? │?? └── views.cpython-35.pyc
│?? ├── templates
│?? │?? └── core
│?? │??     ├── base.html
│?? │??     ├── footer.html
│?? │??     ├── index.html
│?? │??     ├── login.html
│?? │??     ├── navbar.html
│?? │??     ├── nav.html
│?? │??     ├── partial_settings_menu.html
│?? │??     ├── password.html
│?? │??     ├── picture.html
│?? │??     ├── profile.html
│?? │??     └── registration.html
│?? ├── tests.py
│?? ├── urls.py
│?? └── views.py
├── db.sqlite3
├── funderpreneur
│?? ├── fonts
│?? │?? ├── material-design-icons
│?? │?? │?? ├── Material-Design-Iconsd41d.eot
│?? │?? │?? ├── Material-Design-Icons.svg
│?? │?? │?? ├── Material-Design-Icons.ttf
│?? │?? │?? └── Material-Design-Icons.woff
│?? │?? └── roboto
│?? │??     ├── Roboto-Bold.ttf
│?? │??     ├── Roboto-Bold.woff
│?? │??     ├── Roboto-Light.ttf
│?? │??     ├── Roboto-Light.woff
│?? │??     ├── Roboto-Medium.ttf
│?? │??     ├── Roboto-Medium.woff
│?? │??     ├── Roboto-Regular.ttf
│?? │??     ├── Roboto-Regular.woff
│?? │??     ├── Roboto-Thin.ttf
│?? │??     └── Roboto-Thin.woff
│?? ├── __init__.py
│?? ├── __pycache__
│?? │?? ├── __init__.cpython-35.pyc
│?? │?? ├── settings.cpython-35.pyc
│?? │?? ├── urls.cpython-35.pyc
│?? │?? └── wsgi.cpython-35.pyc
│?? ├── settings.py
│?? ├── static
│?? │?? ├── css
│?? │?? │?? ├── account-settings.css
│?? │?? │?? ├── bootstrap.min.css
│?? │?? │?? ├── custom-materialize.css
│?? │?? │?? ├── footer.css
│?? │?? │?? ├── high-rise-building.jpg
│?? │?? │?? ├── materialize.css
│?? │?? │?? ├── navbar.css
│?? │?? │?? ├── navbar-top-fixed.css
│?? │?? │?? ├── style2.css
│?? │?? │?? └── style.css
│?? │?? ├── humans.txt
│?? │?? ├── img
│?? │?? │?? └── buet_logo.png
│?? │?? └── js
│?? │??     ├── bootstrap.min.js
│?? │??     ├── circular-progress-jquery.js
│?? │??     ├── jquery-1.11.2.min.js
│?? │??     ├── jquery-slim.min.js
│?? │??     ├── jquery.waypoints.min.js
│?? │??     ├── materialize.js
│?? │??     ├── popper.min.js
│?? │??     ├── profile-validation.js
│?? │??     └── registration-validation.js
│?? ├── urls.py
│?? └── wsgi.py
├── manage.py
├── media
├── Pipfile
├── Procfile
├── README.md
├── requirements.txt
├── runtime.txt
└── staticfiles

Answer 1

I also had this problem, but by adding

python-decouple==3.1

into the requirements.txt file, I was able to get past it!