def get_event_abi(abi, event_name):
    """Helper function that extracts the event abi from the given abi.

    Args:
        abi (list): the contract abi
        event_name (str): the event name

    Returns:
        dict: the event specific abi
    """
    for entry in abi:
        if 'name' in entry.keys() and entry['name'] == event_name and \
                entry['type'] == "event":
            return entry
    raise ValueError(
        'Event `{0}` not found in the contract abi'.format(event_name))