def _get_api_version_from_accept_header(api_version_header: str):
    """Split input string and return the api version.

    Input must be of the format:
    [something];version=[some version]

    :param str api_version_header: value of 'Accept' header

    :returns: api version specified in the input string.
        Returns 0.0 by default.
    """
    api_version = '0.0'
    if api_version_header:
        tokens = api_version_header.split(";")
        if len(tokens) == 2:
            tokens = tokens[1].split("=")
            if len(tokens) == 2:
                api_version = tokens[1]
    return api_version