Amir Michail schrieb: > Diez B. Roggisch wrote: >> Amir Michail schrieb: >>> Paolo Pantaleo wrote: >>>> 27 Aug 2006 00:44:33 -0700, Amir Michail <[EMAIL PROTECTED]>: >>>>> Hi, >>>>> >>>>> Trying to open a file for writing that is already open for writing >>>>> should result in an exception. >>>>> >>>>> It's all too easy to accidentally open a shelve for writing twice and >>>>> this can lead to hard to track down database corruption errors. >>>>> >>>>> Amir >>>>> >>>>> -- >>>>> http://mail.python.org/mailman/listinfo/python-list >>>>> >>>> Even if it could be strange, the OS usually allow you to open a file >>>> twice, that's up to the programmer to ensure the consistency of the >>>> operations. >>>> >>>> PAolo >>>> >>> But if this is usually a serious bug, shouldn't an exception be raised? >> executing "rm -rf /" via subprocess is usually also a bad idea. So? No >> language can prevent you from doing such mistake. And there is no way to >> know if a file is opened twice - it might that you open the same file >> twice via e.g. a network share. No way to know that it is the same file. >> >> Diez > > The scenario I have in mind is something like this: > > def f(): > db=shelve.open('test.db', 'c') > # do some stuff with db > g() > db.close() > > def g(): > db=shelve.open('test.db', 'c') > # do some stuff with db > db.close() > > I think it would be easy for python to check for this problem in > scenarios like this.
You are requesting a general solution for a very particular problem. As I pointed out, that solution is unlikely to work reliably - if not infeasible at all. If you really have problems as the above, use a custom wrapper for shelve that prevents _you_ from making that mistake. Diez -- http://mail.python.org/mailman/listinfo/python-list
