Return DateOffset object associated with rule name

    Examples
    --------
    get_offset('EOM') --> BMonthEnd(1)

def get_offset(name):
    """
    Return DateOffset object associated with rule name

    Examples
    --------
    get_offset('EOM') --> BMonthEnd(1)
    """
    if name not in libfreqs._dont_uppercase:
        name = name.upper()
        name = libfreqs._lite_rule_alias.get(name, name)
        name = libfreqs._lite_rule_alias.get(name.lower(), name)
    else:
        name = libfreqs._lite_rule_alias.get(name, name)

    if name not in _offset_map:
        try:
            split = name.split('-')
            klass = prefix_mapping[split[0]]
            # handles case where there's no suffix (and will TypeError if too
            # many '-')
            offset = klass._from_name(*split[1:])
        except (ValueError, TypeError, KeyError):
            # bad prefix or suffix
            raise ValueError(libfreqs.INVALID_FREQ_ERR_MSG.format(name))
        # cache
        _offset_map[name] = offset

    return _offset_map[name]