pip install requirements.txt issue when deploying Django app on Heroku

Question

I am trying to deploy my django app on Heroku using the following guidance: https://devcenter.heroku.com/articles/deploying-python . I reached the point where I have to create and populate the "requirements.txt" file with the following command:

$ pip install -r requirements.txt

However, I get the following error message

You must give at least one requirement to install (see "pip help install")

I tried two other commands

$ pip install -r requirements.txt requirements.txt
$ pip install --allow-all-external requirements.txt

but in both cases I get the following error

Collecting requirements.txt
/home/bastien/python/framework/scrapping/venv/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:318: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#snimissingwarning.
SNIMissingWarning
/home/bastien/python/framework/scrapping/venv/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
InsecurePlatformWarning

Could you please tell me where the issue is coming from, how I can resolve it using the appropriate command lines or if there is a way to populate the requirements.txt file in any other way? Thanks.

Answer 1

pip install -r requirements.txt does not populate requirements.txt - it reads it as the source of names of packages to install. See https://pip.pypa.io/en/stable/user_guide/#requirements-files for further details.

To capture your current installed package list to a requirements.txt , try pip freeze > requirements.txt .