Can I specify install time dependencies for pip?

Question

I'm looking for a way to mimic pyproject.toml behavior for pip install .

pyproject.toml can specify build-time dependencies, eg if a setup.py needs extra packages to build:

setup.py

from setuptools import setup
import colorama # e.g. - non-standard package
setup(...)

This can be handled by a pyproject.toml

[build-system]
requires = [
    "colorama",  # required for running custom code in setup.py
    "setuptools>=40.8.0",  # required by doc (https://pip.pypa.io/en/stable/reference/build-system/pyproject-toml/)
    "wheel", # required by doc (https://pip.pypa.io/en/stable/reference/build-system/pyproject-toml/)
]
build-backend = "setuptools.build_meta:__legacy__" # required by doc (https://pip.pypa.io/en/stable/reference/build-system/pyproject-toml/)

which will allow python -m build to run.

However, this doesn't solve the issue for pip install <path> , due to pyproject.toml only handling build.

Is there a way to do so for installation as well?

My only thoughts are

1. add a wrapper that installs the required pkg which I don't want to (hoping to stick with just pip install )
2. call subprocess.run(f'pip install {pkg}'); importlib.reload(pkg) subprocess.run(f'pip install {pkg}'); importlib.reload(pkg) which is hacky

Is there a better way?

Answer 1

I have already posted the asnswer in the comments, but since that's depricated here's the official answer:

from pip._internal.commands import create_command

package_names = ['colorama']  # packages to install
arguments = ['--upgrade'] # extra arguments
command = create_command("install", isolated=True) # don't know what isolated does, so maybe that needs to change
command.main(package_names + arguments) # execute it

Note that this is the original function, and it's probably safer to call al those functions

def main(args=None):
    # type: (Optional[List[str]]) -> int
    if args is None:
        args = sys.argv[1:]

    # Configure our deprecation warnings to be sent through loggers
    # deprecation.install_warning_logger() # don't call this

    autocomplete()

    try:
        cmd_name, cmd_args = parse_command(args)
    except PipError as exc:
        sys.stderr.write(f"ERROR: {exc}")
        sys.stderr.write(os.linesep)
        sys.exit(1)

    # Needed for locale.getpreferredencoding(False) to work
    # in pip._internal.utils.encoding.auto_decode
    try:
        locale.setlocale(locale.LC_ALL, "")
    except locale.Error as e:
        # setlocale can apparently crash if locale are uninitialized
        logger.debug("Ignoring error %s when setting locale", e)
    command = create_command(cmd_name, isolated=("--isolated" in cmd_args))

    return command.main(cmd_args)