setup.py

# Try to import setuptools (if it fails, the user needs that package)
try: 
    from setuptools import setup, find_packages
except:
    # Custom error (in case user does not have setuptools)
    class DependencyError(Exception): pass
    raise(DependencyError("Missing python package 'setuptools'.\n  pip install --user setuptools"))

import os

# Convenience function for reading information files
def read(f_name, empty_lines=False):
    text = []
    with open(os.path.join(package_about, f_name)) as f:
        for line in f:
            line = line.strip("\n")
            if (not empty_lines) and (len(line.strip()) == 0): continue
            if (len(line) > 0) and (line[0] == "%"): continue
            text.append(line)
    return text

# Go to the "about" directory in the package directory.
package_about = ""
package_name = read("package_name.txt")[0]
package_about = os.path.join(os.path.dirname(os.path.abspath(__file__)),package_name,"about")

if __name__ == "__main__":
    #      Read in the package description files     
    # ===============================================
    package = package_name
    version =read("version.txt")[0]
    description = read("description.txt")[0]
    keywords = read("keywords.txt")
    classifiers = read("classifiers.txt")
    name, email, git_username = read("author.txt")
    requirements = read("requirements.txt")
    # Call "setup" to formally set up this module.
    setup(
        author = name,
        author_email = email,
        name=package,
        packages=[package],
        include_package_data=True,
        install_requires=requirements,
        version=version,
        url = 'https://github.com/{git_username}/{package}'.format(
            git_username=git_username, package=package),
        download_url = 'https://github.com/{git_username}/{package}/archive/{version}.tar.gz'.format(
            git_username=git_username, package=package, version=version),
        description = description,
        # scripts=[os.path.join(package,"setup.py")],
        keywords = keywords,
        python_requires = '>=3.6',
        license='MIT',
        classifiers=classifiers
    )
    # Attempt to import the module, in case compilation must be
    # done. It is in a try block with an empty catch-all except. THIS
    # IS BAD PRACTICE, but it is possible that the issues are more
    # easily fixed after install. Consider modifying this block for
    # each project to be less all-encompassing.
    try:
        # Import the setup file.
        import importlib
        importlib.import_module(package+".setup")
    except: pass

# 
# Install specific versions of a package with something like:
# 
#   pip install https://github.com/tchlux/packager/archive/1.0.0.zip
# 
# Include external requirements in a `requirements.txt` file like:
#  
#   packager @ https://github.com/tchlux/packager/archive/1.0.0.zip
#