Blender script to add UVspheres along with curve's location and length.

addUVsphere_on_curves2_fit_curvesize1_test3_functionize1.py

def addUVsphereOnCurves(number,scale=0.1):
    import bpy
    import mathutils
    from mathutils import Vector

    objectList = []
    curveList = []
    lengthList = []
    locationList = []

    #---------Function to get length of curves------------
    # Usage: After select one curve to be active, get_length(bpy.context).
    def get_length(context):

        obj_name_original = context.active_object.name
        bpy.ops.object.duplicate_move()
        # the duplicate is active, apply all transforms to get global coordinates
        bpy.ops.object.transform_apply(location=True, rotation=True, scale=True)
        # convert to mesh
        bpy.ops.object.convert(target='MESH', keep_original=False)
        _data = context.active_object.data
        edge_length = 0
        for edge in _data.edges:
            vert0 = _data.vertices[edge.vertices[0]].co
            vert1 = _data.vertices[edge.vertices[1]].co
            edge_length += (vert0-vert1).length
        # deal with trailing float smear
        edge_length = '{:.6f}'.format(edge_length)
        #print(edge_length)
        # stick into clipboard
        context.window_manager.clipboard = edge_length
        bpy.ops.object.delete()
        context.scene.objects.active = context.scene.objects[obj_name_original]
        context.object.select = True
        #Added return to get value.
        return edge_length


    #---------Make object/location/length lists of curves-------------
    # Object list of curves.
    def makeObjectList(number):
        for i in range(number):
            if i < 1:
                objectList.append(bpy.data.objects["Curve"])
            elif 1 <= i < 10:
                objectList.append(bpy.data.objects["Curve.00" + str(i)])
            else:
                objectList.append(bpy.data.objects["Curve.0" + str(i)])

    # Make curve list because bpy.data.objects can't switch 2D to 3D. bpy.data.curves can do.
    def makeCurveList():
        for i in objectList:
            curveList.append(bpy.data.curves[i.name])

    #Switch 3D from 2D of curve not to get error in get_length.
    def switch2dTo3d():
        for i in curveList:
            i.dimensions = '3D'

    # In for loop of objectList. Firstly deselect all object. Activate one object. Select this object. Gettin length of curve, deselect it.
    def executeGetLength():
        bpy.ops.object.select_all(action='DESELECT')
        for i in objectList:
            bpy.context.scene.objects.active = i
            i.select = True
            lengthList.append(get_length(bpy.context))
            i.select = False
     
    # Return from 3D to 2D.
    def switch3dTo2d():
        for i in curveList:
            i.dimensions = '2D'
     
    # Make locationList of curve from objectList.
    def makeLocationList():
        for i in objectList:
            locationList.append(i.location)
     
     
    #--------Add objects where curves are----------
    # Add UVsphere along with locationList. size come from lengthList.
    def AddUVsphere(scale):
        for i,d in enumerate(locationList):
            # divide size by 10 for too large if default.
            bpy.ops.mesh.primitive_uv_sphere_add(location=d, size=float(lengthList[i])*scale)
        
    # Execution function
    makeObjectList(number)
    makeCurveList()
    switch2dTo3d()
    executeGetLength()
    switch3dTo2d()
    makeLocationList()
    AddUVsphere(scale)


# Number is curve's number in order like Curve ~ Curve.065. Scale is scale of UVsphere. 
#addUVsphereOnCurves(number=65,scale=0.1)