[New-bugs-announce] [issue6565] improper use of __setitem__ in ElementTree for Python 3.1

[Andre Roberge]

New submission from Andre Roberge <andre.roberge at gmail.com>:

I have a function to replace the content of an ElementTree Element by
that of another one which works using Python 2 but not with Python 3.
I get an assertion error.  

It was suggested on the Python list that the problem is that in Python 3
slice assignments are done with __setitem__ rather than __setslice__ but
ElementTree has not been adapted to that -- hence the title given to
this bug.

The function that I use to demonstrate this (with a workaround solution)
is as follows:

def replace_element(elem, replacement):
    '''replace the content of an ElementTree Element by that of
another
       one.
    '''
    elem.clear()
    elem.text = replacement.text
    elem.tail = replacement.tail
    elem.tag = replacement.tag
    elem.attrib = replacement.attrib
    try:
        elem[:] = replacement[:]  # works with Python 2.5 but not 3.1
    except AssertionError:
        del elem[:]
        for child in replacement:
            elem.append(child)

I have included a small test file which demonstrate the behaviour.

----------
components: Library (Lib)
files: test.py
messages: 90891
nosy: aroberge
severity: normal
status: open
title: improper use of __setitem__ in ElementTree for Python 3.1
type: behavior
versions: Python 3.1
Added file: http://bugs.python.org/file14560/test.py

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