[OE-core] "inherit setuptools" versus "inherit pypi" -- a python style question

[Robert P. J. Day]

  possibly a "best practices" question ... regarding recipe for
"python-psutil" (although this applies for numerous python recipes),
wind river linux 8 has a recipe for python-psutil_2.2.1.bb which
inherits pypi:

  RDEPENDS_${PN} += " \
    python-subprocess \
    "

  inherit pypi

a newer recipe i ran across in-house that someone else set up,
python-psutil_3.2.1.bb, instead inherits setuptools and gets the
source from github:

  inherit setuptools

  # 3.2.1 tag
  SRCREV = "99f6abf9bcff3abff815b8e93c8cd2fbe26487a2"
  SRC_URI = "git://github.com/giampaolo/psutil.git;protocol=https"

  S = "${WORKDIR}/git"

  RDEPENDS_${PN} += " \
    python-subprocess \
    "

finally, the current (meta-openembedded) meta-python recipe,
python-psutil_5.0.1.bb, inherits both:

  inherit pypi setuptools
  require python-psutil.inc

and the corresponding .inc file contains:

  RDEPENDS_${PN} += " \
    ${PYTHON_PN}-shell \
    ${PYTHON_PN}-subprocess \
    ${PYTHON_PN}-threading \
  "

so the first recipe inherits pypi, the second one inherits setuptools,
and the third inherits *both*. what is the *preferred* style?

  i'm assuming that if a python module is availably via pypi, then
you'd go with that; otherwise, just use regular setuptools. and not
being a python guru, why does that third recipe need to inherit both?

  i did a quick grep of the current meta-python layer to see the
frequency of each, and got:

  $ grep -r "inherit pypi$" | wc -l
  13
  $

  $ grep -r "inherit pypi setuptools" | wc -l
  157
  $

so, clearly, far more python recipes inherit both as opposed to just
inheriting pypi. i don't know enough about python recipes to
appreciate if this distinction is necessary or not. can someone
clarify this? thanks.

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================