def complex_vct_str ( vct , format = '%.5g%-+.5gj' ) :
    """Convert vector of complex types to string"""
    try :
        lst = [] 
        for c in vct :
            cc   = complex ( c )
            item = format % ( cc.real , cc.imag )
            lst.append ( cc )        
        return '[ ' + ', '.join ( lst ) + ' ]'  
    except TypeError :
        pass
    return complex_vct_str ( vct , format = '%.5g%-+.5gj' )