[Tutor] making a custom file parser?

[Chris Fuller]

If it's unambiguous as to which tags are closed and which are not, then it's 
pretty easy to preprocess the file into valid XML.  Scan for the naughty bits 
(single quotes) and insert escape characters, replace with something else, 
etc., then scan for the unterminated tags and throw in a "/" at the end.

Anyhow, if there's no tree structure, or its only one level deep, using 
ElementTree is probably overkill and just gives you lots of leaking 
abstractions to plug for little benefit.  Why not just scan the file directly?

Cheers

On Saturday 07 January 2012, Alex Hall wrote:
> Hello all,
> I have a file with xml-ish code in it, the definitions for units in a
> real-time strategy game. I say xml-ish because the tags are like xml,
> but no quotes are used and most tags do not have to end. Also,
> comments in this file are prefaced by an apostrophe, and there is no
> multi-line commenting syntax. For example:
> 
> <unit>
> <number=1>
> <name=my unit>
> <canMove=True>
> <canCarry=unit2, unit3, unit4>
> 'this line is a comment
> </unit>
> 
> The game is not mine, but I would like to put together a python
> interface to more easily manage custom units for it. To do that, I
> have to be able to parse these files, but elementtree does not seem to
> like them very much. I imagine it is due to the lack of quotes, the
> non-standard commenting method, and the lack of closing tags. I think
> my only recourse here is to create my own parser and tell elementtree
> to use that. The docs say this is possible, but they also seem to
> indicate that the parser has to already exist in the elementtree
> package and there is no mention of making one's own method for
> parsing. Even if this were possible, though, I am not sure how to go
> about it. I can of course strip comments, but that is as far as I have
> gotten.
> 
> Bottom line: can I create a method and tell elementtree to parse using
> it, and what would such a function look like (generally) if I can?
> Thanks!