Can anyone Pythonize this lexical algorithm?

Paul McGuire ptmcg at austin.rr.com
Thu Oct 9 15:58:47 EDT 2008


On Oct 9, 7:29 am, ShashiGowda <connect2sha... at gmail.com> wrote:
> I am writing a package manager and stuck unable to write the version
> sorting function the algorithm is herehttp://www.linux.gr/cgi-bin/man/man2html?deb-version+5
> and all other info is also in it please tell me how to do lexical
> comparision in python it'll be cool if you just write the code!

On Oct 9, 7:29 am, ShashiGowda <connect2sha... at gmail.com> wrote:
> I am writing a package manager and stuck unable to write the version
> sorting function the algorithm is herehttp://www.linux.gr/cgi-bin/man/man2html?deb-version+5
> and all other info is also in it please tell me how to do lexical
> comparision in python it'll be cool if you just write the code!

Step 1.  Define a class, call it something like PackageVersion, with
an __init__ method that takes an string containing the version
string.  In the body of __init__, use regular expressions, pyparsing,
str methods, whatever, to break up the version into the individual
fields.
Step 2.  Implement a __cmp__ method on PackageVersion that performs
the desired version comparison logic.

Take a crack at writing some code, and come back with specific
questions.  I doubt your hopes for coolness will be met.

-- Paul




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