On Jan 18, 9:10 am, Terry Reedy <tjre...@udel.edu> wrote: > Martin v. Löwis wrote: > >>> Does he intend to maintain two separate codebases, one 2.x and the > >>> other 3.x? > >> I think I have no other choice. > >> Why? Is theoretically possible to maintain an unique code base for > >> both 2.x and 3.x? > > > That is certainly possible! One might have to make tradeoffs wrt. > > readability sometimes, but I found that this approach works quite > > well for Django. I think Mark Hammond is also working on maintaining > > a single code base for both 2.x and 3.x, for PythonWin. > > Where 'single codebase' means that the code runs as is in 2.x and as > autoconverted by 2to3 (or possibly a custom comverter) in 3.x. > > One barrier to doing this is when the 2.x code has a mix of string > literals with some being character strings that should not have 'b' > prepended and some being true byte strings that should have 'b' > prepended. (Many programs do not have such a mix.) > > One approach to dealing with string constants I have not yet seen > discussed here is to put them all in separate file(s) to be imported. > Group the text and bytes separately. Them marking the bytes with a 'b', > either by hand or program would be easy.
(1) How would this work for somebody who wanted/needed to support 2.5 and earlier? (2) Assuming supporting only 2.6 and 3.x: Suppose you have this line: if binary_data[:4] == "PK\x03\x04": # signature of ZIP file Plan A: Change original to: if binary_data[:4] == ZIPFILE_SIG: # "PK\x03\x04" Add this to the bytes section of the separate file: ZIPFILE_SIG = "PK\x03\x04" [somewhat later] Change the above to: ZIPFILE_SIG = b"PK\x03\x04" [once per original file] Add near the top: from separatefile import * Plan B: Change original to: if binary_data[:4] == ZIPFILE_SIG: # "PK\x03\x04" Add this to the separate file: ZIPFILE_SIG = b"PK\x03\x04" [once per original file] Add near the top: from separatefile import * Plan C: Change original to: if binary_data[:4] == b"PK\3\4": # signature of ZIP file Unless I'm gravely mistaken, you seem to be suggesting Plan A or some variety thereof -- what advantages do you see in this over Plan C? -- http://mail.python.org/mailman/listinfo/python-list
