import bpy
C = bpy.context

mask = bpy.data.objects['Mask']
xmin = 100000000
xmax = -100000000
ymin = 100000000
ymax = -100000000
for v in mask.data.vertices:
    if v.co[0]<xmin: xmin = v.co[0]
    if v.co[0]>xmax: xmax = v.co[0]
    if v.co[1]<ymin: ymin = v.co[1]
    if v.co[1]>ymax: ymax = v.co[1]


others = [o for o in bpy.data.objects if o != mask]

print(xmin, xmax,ymin,ymax)

for o in others:
    if o.type == "":
        for spline in o.data.splines:
            for p in spline.points:
                if p.co[0] < xmin: p.select = True
                elif p.co[0] > xmax: p.select = True
                elif p.co[1] < ymin: p.select = True
                elif p.co[1] > ymax: p.select = True
            if len(spline.points)==0:
                o.data.splines.remove(splines)
        
        C.scene.objects.active = o
        bpy.ops.object.editmode_toggle()
        bpy.ops.curve.delete(type='SELECTED')
        bpy.ops.object.editmode_toggle()
    elif o.type == "MESH":
        for v in o.data.vertices:
            if v.co[0] < xmin: v.select = True
            elif v.co[0] > xmax: v.select = True
            elif v.co[1] < ymin: v.select = True
            elif v.co[1] > ymax: v.select = True
        
        C.scene.objects.active = o
        bpy.ops.object.editmode_toggle()
        bpy.ops.mesh.delete(type="VERT")
        bpy.ops.object.editmode_toggle()