On Mar 26, 2008, at 7:34 PM, Chris McDonough wrote: > zooko wrote: http://mail.python.org/pipermail/python-dev/2008-March/078243.html
>> Here is a simple proposal: make the standard Python "import" >> mechanism notice eggs on the PYTHONPATH and insert them (into the >> *same* location) on the sys.path. >> This eliminates the #1 problem with eggs -- that they don't >> easily work when installing them into places other than your site- >> packages and that if you allow any of them to be installed on >> your system then they take precedence over your non-egg packages >> even you explicitly put those other packages earlier in your >> PYTHONPATH. (That latter behavior is very disagreeable to more >> than a few prorgammers.) > > Sorry if I'm out of the loop and there's some subtlety here that > I'm disregarding, but it doesn't appear that either of the issues > you mention is a actually problem with eggs. These are instead > problems with how eggs get installed by easy_install (which uses > a .pth file to extend sys.path). It's reasonable to put eggs on > the PYTHONPATH manually (e.g. sys.path.append('/path/to/some.egg')) > instead of using easy_install to install them. Yes, you are missing something. While many programmers, such as yourself and Lennart Regebro (who posted to this thread) find the current eggs system to be perfectly convenient and to Just Work, many others, such as Glyph Lefkowitz (who posted to a related thread) find them to be so annoying that they actively ensure that no eggs are ever allowed to touch their system. The reasons for this latter problem are two: 1. You can't conveniently install eggs into a non-system directory, such as ~/my-python-stuff. 2. If you allow even a single egg to be installed into your PYTHONPATH, it will change the semantics of your PYTHONPATH. Both of these problems are directly caused by the need for eggs to hack your site.py. If Python automatically added eggs found in the PYTHONPATH to the sys.path, both of these problems would go away. I am skeptical that the current proposals to define a new database for installed packages will fare any better than the current eggs scheme does in this respect. This issue is important to me, because the benefits of eggs grow superlinearly with the number of good programmers who use them. They are a tool for re-using source code -- a tool for cooperation between programmers. To gain the greatest benefits at this point we do not need to add new features to eggs, we need to make them more palatable to more good programmers. I am skeptical that prorgammers are going to be willing to use a new database format. They already have a database -- their filesystem -- and they already have the tools to control it -- mv, rm, and PYTHONPATH. Many of them already hate the existence the "easy_instlal.pth" database file, and I don't see why a new database file would be any different. My proposal makes the current benefits of eggs -- clean, easy code re- use among programmers -- more compatible with their current tools -- mv, rm, and PYTHONPATH. It is also forward-compatible with more sophisticated proposals to add features like uninstall and operating system integration. By the way, since I posted my proposal two weeks ago I have pointed a couple of Python hackers who currently refuse to use eggs at the URL: http://mail.python.org/pipermail/python-dev/2008-March/078243.html They both agreed that it made perfect sense. I told one of them about the alternate proposal to define a new database file to contain a list of installed packages, and he sighed and rolled his eyes and said "So they are planning to reinvent apt!". Regards, Zooko _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com