Re: Read-only attribute in module
Terry Reedy wrote On 2/10/2012 6:11 AM, mloskot wrote: The intent of xyz.flag is that it is a value set by the module internally. xyz is a module wrapping a C library. The C library defines concept of a global flag set by the C functions at some events, so user can check value of this flag. I can provide access to it with function: xyz.get_flag() If the value of the flag can change during a run, I would do that. Otherwise, you have to make sure the local copy keeps in sync. Users might also think that it is a true constant that they could read once. I understand that you might be concerned that one person in a multi-programmer project might decide to rebind xyz.flag and mess up everyone else. I think the real solution might be an option to freeze an entire module. Terry, Thanks for your really helpful notes. Best regards, - -- Mateusz Loskot http://mateusz.loskot.net -- View this message in context: http://python.6.n6.nabble.com/Read-only-attribute-in-module-tp4378950p4464760.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
Re: Read-only attribute in module
Terry Reedy wrote On 2/9/2012 6:43 AM, Mateusz Loskot wrote: import xyz print(xyz.flag) # OK xyz.flag = 0 # error due to no write access Why prevent that? If you called it 'FLAG', that would indicate that it is a constant that should not be changed. While Python make some effort to prevent bugs, it is generally a 'consenting adults' language. Terry, The intent of xyz.flag is that it is a value set by the module internally. xyz is a module wrapping a C library. The C library defines concept of a global flag set by the C functions at some events, so user can check value of this flag. I can provide access to it with function: xyz.get_flag() But, I thought it would be more convenient to have a read-only property in scope of the module. Sometimes, especially when wrapping C code, it is not possible to map C API semantics to Python concepts as 1:1. - -- Mateusz Loskot http://mateusz.loskot.net -- View this message in context: http://python.6.n6.nabble.com/Read-only-attribute-in-module-tp4378950p4382967.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
Re: Read-only attribute in module
Ben Finney-10 wrote Mateusz Loskot lt;mateusz@gt; writes: So, the following import xyz print(xyz.flag) # OK xyz.flag = 0# error due to no write access PEP 8 lt;URL:http://www.python.org/dev/peps/pep-0008/gt; gives the style guide for Python code (strictly for the standard library, but it is recommended for all Python code). Ben, That's what I thought really. Thank you for confirming the sanity of the style-powered conventions. Best regards, - -- Mateusz Loskot http://mateusz.loskot.net -- View this message in context: http://python.6.n6.nabble.com/Read-only-attribute-in-module-tp4378950p4380150.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I tell incomplete input from invalid input?
Terry Reedy wrote On 1/11/2012 8:50 AM, Mateusz Loskot wrote: Unfortunately, this FAQ is either old or incomplete thus incorrect. If you have a suggested change to the current text, please submit it to the tracker at bugs.python.org Yes, this is quite obvious procedure to me, but first I wanted to discuss the problem and to try to find proper solution worth to be included in the FAQ. Best regards, - -- Mateusz Loskot http://mateusz.loskot.net -- View this message in context: http://python.6.n6.nabble.com/How-do-I-tell-incomplete-input-from-invalid-input-tp3585241p3632798.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
