enable install with pip from github

[philbarker]

I wanted to install with
$ pip3 install -e git+https://github.com/tombaker/csv2shex.git#egg=csv2shex
and then import relevant classes, but there were problems.

• problem with pip v50 described here ModuleNotFoundError: No module named 'setuptools._distutils' pypa/setuptools#2353
• giving pip info necessary to build egg and find modules in it.

Happy to amend PR if there are elements you don't like.

[tombaker]

@philbarker
This looks okay, though I'm curious about the notion of an editable install that uses a URL. I guess that simply means that each time you import, it will pull from the repository? Also, I thought pyproject.toml was supposed to make setup.py unnecessary, though I see no harm in having both.

[philbarker]

I think it only inports from the repo if you upgrade from pip.
Also, I think editable installs are the only case where setup.py is needed, at least that is the impression I got from https://stackoverflow.com/questions/62983756/what-is-pyproject-toml

Thanks for merging.

[tombaker]

@philbarker I have an editable install with just pyproject.toml - see the instructions in README.rst. The part I do not understand is what it means to pip install a remote repo in editable mode. The -s option in flit install -s makes it editable. For more discussion, see Brian Okken.

[philbarker]

pip install from a remote repo in editable mode combines git clone with a pip -e editable install. It means that the csv2shex dependency for what I am writing can sit in the requirements.txt along with all the other requirements that I manage with pip. But it also gives me a copy of the source as a local git repo (in venv/src/csv2shex, so outside the project) that I can edit when things go wrong.