def decimal2dm(decimal_degrees):
    """ Converts a floating point number of degrees to the equivalent
    number of degrees and minutes, which are returned as a 2-element list.
    If 'decimal_degrees' is negative, only degrees (1st element of returned list)
    will be negative, minutes (2nd element) will always be positive.

    Example:
    >>> decimal2dm(121.135)
    [121, 8.100000000000307]
    >>> decimal2dm(-121.135)
    [-121, 8.100000000000307]
    
    """

    degrees = int(decimal_degrees) 
    minutes = abs(decimal_degrees - degrees) * 60
    return [degrees, minutes]