[lxml-dev] finding the line number of a parsed element

[Martijn Faassen]

Stefan Behnel wrote:
[snip]
> I personally prefer "_line" over "line", as this only applies to parsed
> elements, not all of them, so this is more of a half-working API.
> Additionally, any additional attribute there goes off the list of children
> accessible in objectify.

I really don't like _line. The underscore in a strong Python convention 
indicates "implementation details", and code external to a class should 
*not* be touching attributes which start with an underscore unless it 
knows it's going to do something evil. Initial underscores are not meant 
to indicate half-working APIs or something.

Accessing _line is not evil, it's just not guaranteed to be correct if 
you manipulate a parsed tree, or create a tree from scratch. This should 
simply be documented.

(Are we sure it's half-working, anyway? Does libxml2 start counting 
lines at 0 or at 1? If at 1 then 0 is entirely unambiguous and we may be 
able to return None instead reliably)

Anyway, to conclude, I think 'line' is just fine - I believe that's a 
complete API, if only not a great one if we can't distinguish between 
line 0 and "no line known".

Regards,

Martijn