def distL1 ( x1 , y1 , x2 , y2 ) : return int ( abs ( x2 - x1 ) + abs ( y2 - y1 ) + .5 )
finding the minimum distance between two points from a lsit of points in python
Compute the L1 - norm ( Manhattan ) distance between two points .
def distL1(x1,y1,x2,y2):
    """Compute the L1-norm (Manhattan) distance between two points.

    The distance is rounded to the closest integer, for compatibility
    with the TSPLIB convention.

    The two points are located on coordinates (x1,y1) and (x2,y2),
    sent as parameters"""
    return int(abs(x2-x1) + abs(y2-y1)+.5)