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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_po_paths(locales=[]):
 """Returns paths to all relevant po files in the current project."""

    basedirs = [os.path.join('conf', 'locale'), 'locale']
    if os.environ.get('DJANGO_SETTINGS_MODULE'):
        from django.conf import settings
        basedirs.extend(settings.LOCALE_PATHS)

    # Gather existing directories.
    basedirs = set(map(os.path.abspath, filter(os.path.isdir, basedirs)))

    if not basedirs:
        raise CommandError("This script should be run from the Django SVN tree or your project or app tree, or with the settings module specified.")

    po_paths = []
    for basedir in basedirs:
        for locale in locales:
            basedir_locale = os.path.join(basedir, locale, 'LC_MESSAGES')
            for dirpath, dirnames, filenames in os.walk(basedir_locale):
                for f in filenames:
                    if f.endswith('.po'):
                        po_paths.append(os.path.join(dirpath, f))
    return po_paths