(coord)
return tuple(coord_norm)
Normalise the coord argument.
    Coord sys are either 'E','G', 'C' or 'X' if undefined.

    Input: either a string or a sequence of string.

    Output: a tuple of two strings, each being one of the norm coord sys name
            above.

    eg, 'E' -> ['E','E'], ['Ecliptic','G'] -> ['E','G']
    None -> ['X','X'] etc.
Normalise the coord argument.
    Coord sys are either 'E','G', 'C' or 'X' if undefined.
Normalise the coord argument . Coord sys are either E G C or X if undefined .
def normalise_coord(coord):
    """Normalise the coord argument.
    Coord sys are either 'E','G', 'C' or 'X' if undefined.

    Input: either a string or a sequence of string.

    Output: a tuple of two strings, each being one of the norm coord sys name
            above.

    eg, 'E' -> ['E','E'], ['Ecliptic','G'] -> ['E','G']
    None -> ['X','X'] etc.
    """
    coord_norm = []
    if coord is None:
        coord = (None, None)
    coord = tuple(coord)
    if len(coord) > 2:
        raise TypeError(
            "Coordinate must be a string (G[alactic],"
            " E[cliptic] or C[elestial])"
            " or a sequence of 2 strings"
        )
    for x in coord:
        coord_norm.append(check_coord(x))
    if len(coord_norm) < 2:
        coord_norm.append(coord_norm[0])
    return tuple(coord_norm)
def normalise_coord ( coord ) : coord_norm = [ ] if coord is None : coord = ( None , None ) coord = tuple ( coord ) if len ( coord ) > 2 : raise TypeError ( "Coordinate must be a string (G[alactic]," " E[cliptic] or C[elestial])" " or a sequence of 2 strings" ) for x in coord : coord_norm . append ( check_coord ( x ) ) if len ( coord_norm ) < 2 : coord_norm . append ( coord_norm [ 0 ] ) return tuple ( coord_norm )