On Tue, 23 May 2000, Peter Funk wrote:
Python 1.6 reports a bad magic error, when someone tries to import a .pyc file compiled by Python 1.5.2. AFAIK only new features have been added. So why it isn't possible to use these old files in Python 1.6?
Peter, In theory, perhaps it could; I don't know if the extra work is worth it, however. What's happening is that the .pyc magic number changed because the marshal format has been extended to support Unicode string objects. The old format should still be readable, but there's nothing in the .pyc loader that supports the acceptance of multiple versions of the marshal format. Is there reason to think that's a substantial problem for users, given the automatic recompilation of bytecode from source? The only serious problems I can see are when multiple versions of the interpreter are being used on the same collection of source files (because the re-compilation occurs more often and affects performance), and when *only* .pyc/.pyo files are available. Do you have reason to suspect that either case is sufficiently common to complicate the .pyc loader, or is there another reason that I've missed (very possible, I admit)? -Fred -- Fred L. Drake, Jr. <fdrake at acm.org>