On Wed, Jul 22, 2020 at 1:27 PM Paul Moore <p.f.mo...@gmail.com> wrote: > > On Wed, 22 Jul 2020 at 19:31, David Mathog <dmat...@gmail.com> wrote: > > but that shebang has to be corrected when the installation is moved to a > > normal > > environment, which my code is doing now.) > > Moving files that are installed by Python packaging tools isn't > supported. It might work, and you can probably make it work with some > effort, but it's very much a case of "don't do it unless you know what > you're doing". Correcting shebang lines is definitely something you > will need to do.
I understand that moving files is iffy. However, given that I want only 1 copy of each installed python package on the system and I need to be able to install different versions of the same package (to resolve module version number conflicts between packages), moving the files around and replacing most copies with links to the single copy seemed like the only way to go. Here: https://www.python.org/dev/peps/pep-0394/#recommendation It says: When packaging third party Python scripts, distributors are encouraged to change less specific shebangs to more specific ones. This ensures software is used with the latest version of Python available, and it can remove a dependency on Python 2. The details on what specifics to set are left to the distributors; though. Example specifics could include: Changing python shebangs to python3 when Python 3.x is supported. Changing python shebangs to python2 when Python 3.x is not yet supported. Changing python3 shebangs to python3.8 if the software is built with Python 3.8. and then immediately after it says: When a virtual environment (created by the PEP 405 venv package or a similar tool such as virtualenv or conda) is active, the python command should refer to the virtual environment's interpreter and should always be available. The python3 or python2 command (according to the environment's interpreter version) should also be available. Which seems to be exactly the opposite of the preceding stanza. Ie, "always be as specific as possible" then "be general, and also provide specific" Personally I think the generic use of "python" both in shebangs and when invoking scripts as "python script" should be deprecated, with warnings from the installers to force developers to strip it out. It only works now by chance. Sure, there is a high probability it will work, but if one is on the wrong system it fails. If python4 (whenever it arrives) is not fully backwards compatible with python3 the generic use of "python" is going to cause untold grief. Whereas in that scenario all the code which uses "python3" should continue to function normally. Regards, David Mathog -- Distutils-SIG mailing list -- distutils-sig@python.org To unsubscribe send an email to distutils-sig-le...@python.org https://mail.python.org/mailman3/lists/distutils-sig.python.org/ Message archived at https://mail.python.org/archives/list/distutils-sig@python.org/message/HAZUEGH7D7Y3PDMSYVNXHLYT6YMQLYUW/
