Dynamically creating properties?

[DevPlayer]

On Oct 27, 3:59 pm, Andy Dingley <ding... at codesmiths.com> wrote:
> I have some XML, with a variable and somewhat unknown structure. I'd
> like to encapsulate this in a Python class and expose the text of the
> elements within as properties.
>
> How can I dynamically generate properties (or methods) and add them to
> my class?  I can easily produce a dictionary of the required element
> names and their text values, but how do I create new properties at run
> time?
>
> Thanks,

    class MyX(object):
        pass
    myx = myx()

    xml_tag = parse( file.readline() )

    # should be a valid python named-reference syntax,
    # although any object that can be a valid dict key is allowed.
    # generally valid python named reference would be the answer to
your question
    attribute = validate( xml_tag )

    # dynamicly named property
    setattr( myx, attribute, property(get_func, set_func, del_func,
attr_doc) )

    # "dynamicly named method"
    # really should be a valid python named-reference syntax
    myfunc_name = validate(myfunc_name)

    def somefunc(x):
        return x+x
    # or
    somefunc = lambda x: x + x

    setattr( myx, myfunc_name, somefunc )


So beaware of:
    # \\\\\\\\\\\\\\\\\\\\\\\\\
    setattr(myx, '1', 'one')

    myx.1
        File "<input>", line 1
        x.1
          ^
    SyntaxError: invalid syntax

    # \\\\\\\\\\\\\\\\\\\\\\\\\
    x.'1'
      File "<input>", line 1
        x.'1'
            ^
    SyntaxError: invalid syntax

    # \\\\\\\\\\\\\\\\\\\\\\\\\
    x.__dict__['1']   # returns
    'one'

    x.__dict__        # returns
    {'1': 'one'}

So you should validate your variable names if you are getting them
from somewhere.