[issue16877] Odd behavior of ~ in os.path.abspath and os.path.realpath
Ian Shields added the comment: Regarding last comment. I had missed the comment in documentation fo os.path.join Join one or more path components intelligently. If any component is an absolute path, all previous components (on Windows, including the previous drive letter, if there was one) are thrown away, and joining continues. So the issue is really the behavior of os.path.join where the intelligence in the joining does not recognize that ~ is usually expanded to an absolute path. Consider the following Bash commands: [ian@attic4 testpath]$ pwd /home/ian/testpath [ian@attic4 testpath]$ echo $(cd ~/testpath/..;pwd) /home/ian [ian@attic4 testpath]$ cd /home/ian/~ bash: cd: /home/ian/~: No such file or directory Now consider some Python os.getcwd() '/home/ian/testpath' os.path.join(os.getcwd(), /home/ian) '/home/ian' os.path.expanduser(~) '/home/ian' os.path.join(os.getcwd(), ~) '/home/ian/testpath/~' os.path.expanduser(os.path.abspath(~)) '/home/ian/testpath/~' os.path.abspath(os.path.expanduser(~)) '/home/ian' I find the Python behavior rather odd. I cna live with it now I know about it, but if it is really intentional it would help to document this rather odd behavior somewhat better. -- status: pending - open ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16877 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16877] Odd behavior of ~ in os.path.abspath and os.path.realpath
Ian Shields added the comment: Oddity may be in the eye of the beholder. I've been programming and scripting for about 40 years, including several *IX shells and many other systems. I'm relatively new to Python. Mostly the results of doing things in Python are what I expect. Not doing expansion of a leading tilde when I ask for an absolute path is not what I expect. So to me it's odd. Or different. Or just not what I expect. Substitute unexpected for odd if you like. Sure, tilde expansion wasn't part of the Bourne shell, but it's been in POSIX shells for about the same amount of time that Python has been around, so it's odd to me that Python differs in this way. It's not hard to work around now that I know about it. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16877 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16877] Odd behavior of ~ in os.path.abspath and os.path.realpath
Ian Shields added the comment: David, Tilde expansion is different to globbing. Globbing in Python doesn't automatically do tilde expansion either. glob.glob(~) [] Looking at the documentation, I don't think it would be practical to add documentation to each affected function - there are too many. Apart from abspath and realpath (which started this conversation), there are join, isdir, isfile, isabs, and many others in os.path. posixpath and the other path handling modules. Maybe a note at the top of the module documentation (e.g. http://docs.python.org/3/library/os.path.html) which has two notes already. Something along the line of: Unlike many shells, Python does not automatically do tilde expansion or variable substitution in paths. Use expanduser for tilde expansion or expandvars for variable substitution. Or just simply Use expanduser for tilde expansion or expandvars for variable substitution in paths as the other path functions do not do this automatically. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16877 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16877] Odd behavior of ~ in os.path.abspath and os.path.realpath
Ian Shields added the comment: I think that's an excellent resolution to the problem. Thank you. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16877 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16877] Odd behavior of ~ in os.path.abspath and os.path.realpath
New submission from Ian Shields: Filespecs that start with ~ are not properly handled by os.path.realpath or os.path.abspath (and maybe other functions). Following console output from Fedora 17 using Puthon 3.2 illustrates the issue. Similar issue in 2.7 [ian@attic4 developerworks]$ cd .. [ian@attic4 ~]$ mkdir testpath [ian@attic4 ~]$ cd testpath [ian@attic4 testpath]$ pwd /home/ian/testpath [ian@attic4 testpath]$ python3 Python 3.2.3 (default, Jun 8 2012, 05:36:09) [GCC 4.7.0 20120507 (Red Hat 4.7.0-5)] on linux2 Type help, copyright, credits or license for more information. import os os.path.abspath(~) '/home/ian/testpath/~' os.path.realpath(~/xxx/zzz) '/home/ian/testpath/~/xxx/zzz' os.path.abspath(~/..) '/home/ian/testpath' Function should probably use expanduser to determine if path is already absolute. Documentation at http://docs.python.org/3/library/os.path.html is also misleading as this is not how these functions work if given an absolute path to start with. -- components: None messages: 179170 nosy: ibshields priority: normal severity: normal status: open title: Odd behavior of ~ in os.path.abspath and os.path.realpath type: behavior versions: Python 3.2 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16877 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
