def createDict(data, index):
    """
    Create a new dictionnay from dictionnary key=>values:
    just keep value number 'index' from all values.

    >>> data={10: ("dix", 100, "a"), 20: ("vingt", 200, "b")}
    >>> createDict(data, 0)
    {10: 'dix', 20: 'vingt'}
    >>> createDict(data, 2)
    {10: 'a', 20: 'b'}
    """
    return dict( (key,values[index]) for key, values in data.iteritems() )