[Configobj-develop] Validate Strings as list type

[Michael F. <mi...@vo...>]

Hello guys,

I'm looking at the problem that specifying a list type with validate can 
let strings through unchanged.

The problem is simple enough - validate calls len on arguments and 
assumes that anything with a length is a list!


    try:
        length = len(value)
    except TypeError:
        raise VdtTypeError(value)

The question is how to fix it. As strings are an odd sequence type, I 
propose to add a specific 'isinstance(value, basestring)' check to catch 
strings. I also propose to return list(value) as validate is supposed to 
guarantee the return type of validated values.

A side effect of this is that tuples validated as lists will become 
lists. If this is a problem I could add 'is_tuple' equivalents to the 
'is_list' validate functions... (Differing not on what input they 
accept, but only on the type of the returned value...)

Michael Foord
http://www.manning.com/foord