如何在pythonocc中访问边缘维度？

from OCC.Core.TopoDS import TopoDS_Shape
from OCC.Core.BRepAdaptor import BRepAdaptor_Curve
from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_MakeEdge
from OCC.Core.BRepPrimAPI import BRepPrimAPI_MakeBox

# 创建一个长方体
box = BRepPrimAPI_MakeBox(10, 20, 30).Shape()

# 获取长方体的边缘
edges = []
shape_explorer = TopExp_Explorer(box, TopAbs_EDGE)
while shape_explorer.More():
    edge = TopoDS_Shape(shape_explorer.Current())
    edges.append(edge)
    shape_explorer.Next()

# 选择一个边缘
selected_edge = edges[0]

# 创建一个边缘维度
edge_dim = BRepBuilderAPI_MakeEdge(selected_edge)

# 获取边缘维度的曲线
curve = BRepAdaptor_Curve(edge_dim.Edge())

# 获取边缘维度的起点和终点
start_point = curve.Value(curve.FirstParameter())
end_point = curve.Value(curve.LastParameter())

# 获取边缘维度的长度
length = curve.Length()

# 获取边缘维度的方向
direction = curve.Direction()

# 获取边缘维度的曲率
curvature = curve.Curvature()

# 获取边缘维度的法线
normal = curve.Normal()

# 获取边缘维度的切线
tangent = curve.Tangent()