def get_pres_name(da):
    """ 
        Returns name of pressure dimension in input array
        Author: Dougie Squire
        Date: 03/03/2018
        
        Parameters
        ----------
        da : xarray DataArray
            Array with coordinate corresponding to pressure
        
        Returns
        -------
        name : str
            Name of dimension corresponding to pressure
        
        Examples
        --------
        >>> A = xr.DataArray(np.random.normal(size=(2,2,2,2,2)), 
        ...                  coords=[('lat', np.arange(2)), ('lon', np.arange(2)), 
        ...                          ('depth', np.arange(2)), ('level', np.arange(2)), 
        ...                          ('pfull', np.arange(2))])
        >>> doppyo.utils.get_pres_name(A)
        'pfull'
    """
    
    if 'pfull' in da.dims:
        return 'pfull'
    elif 'phalf' in da.dims:
        return 'phalf'
    else:
        raise KeyError('Unable to determine pressure dimension')
        pass