def sf01(arr):
    """
    swap and then flatten axes 0 and 1
    """
    s = arr.shape
    return arr.swapaxes(0, 1).reshape(s[0] * s[1], *s[2:])
def sf01(arr):
    
    s = arr.shape
    return arr.swapaxes(0, 1).reshape(s[0] * s[1], *s[2:])
def sf01 ( arr ) : s = arr . shape return arr . swapaxes ( 0 , 1 ) . reshape ( s [ 0 ] * s [ 1 ] , * s [ 2 : ] )
swap and then flatten axes 0 and 1
swap and then flatten axes 0 and 1