def platform_sidebar(request, form_data, facets):
    qplatform = form_data.get('platform')
    app_platforms = request.APP.platforms.values()
    ALL = app_platforms.pop(0)

    # The default is to show "All Systems."
    selected = amo.PLATFORM_DICT.get(qplatform, ALL)

    if selected != ALL and app_platforms not in selected:
        # Insert the filtered platform even if it's not a facet.
        app_platforms.append(selected)

    # L10n: "All Systems" means show everything regardless of platform.
    rv = [FacetLink(_(u'All Systems'), dict(platform=ALL.shortname),
                    selected == ALL)]
    for platform in app_platforms:
        rv.append(FacetLink(platform.name, dict(platform=platform.shortname),
                            platform == selected))
    return rv
dataset/ETHPy150Open mozilla/addons-server/src/olympia/search/views.py/platform_sidebar/swapped operands of `not in`