如何用多条短重叠LINESTRING将主LINESTRING分割为n+1段？

我需要用多条重叠的LINESTRING分割主线路（Main Line）。示例中有4条线（为方便查看，Line 1、Line 2、Line 3已添加偏移）：

各线路的WKT定义如下：

from shapely import wkt

main_line = wkt.loads('LINESTRING (461179.6655721677 4507148.788223281, 461217.56786209624 4507181.537033379, 461236.3280996226 4507194.537878151, 461241.7247760045 4507197.640095252, 461258.8379542616 4507210.660701941, 461261.9432857035 4507219.791508417, 461270.90091201715 4507254.590010401, 461271.56385885156 4507303.918307676, 461273.67536588735 4507318.460376316, 461286.2322009634 4507358.346460313, 461302.55653224624 4507403.197152592, 461365.2492823085 4507485.060388609, 461480.4983426857 4507548.512415529, 461580.7367309019 4507618.493483591)')

line_1 = wkt.loads('LINESTRING (461179.6655721677 4507148.788223281, 461217.56786209624 4507181.537033379, 461236.3280996226 4507194.537878151, 461241.7247760045 4507197.640095252, 461258.8379542616 4507210.660701941, 461261.9432857035 4507219.791508417, 461270.90091201715 4507254.590010401, 461271.56385885156 4507303.918307676, 461273.67536588735 4507318.460376316, 461286.2322009634 4507358.346460313, 461302.55653224624 4507403.197152592)')
line_2 = wkt.loads('LINESTRING (461179.6655721677 4507148.788223281, 461217.56786209624 4507181.537033379, 461236.3280996226 4507194.537878151, 461241.7247760045 4507197.640095252, 461258.8379542616 4507210.660701941, 461261.9432857035 4507219.791508417, 461270.90091201715 4507254.590010401, 461271.56385885156 4507303.918307676, 461273.67536588735 4507318.460376316, 461286.2322009634 4507358.346460313, 461302.55653224624 4507403.197152592, 461365.2492823085 4507485.060388609)')
line_3 = wkt.loads('LINESTRING (461179.6655721677 4507148.788223281, 461217.56786209624 4507181.537033379, 461236.3280996226 4507194.537878151, 461241.7247760045 4507197.640095252, 461258.8379542616 4507210.660701941, 461261.9432857035 4507219.791508417, 461270.90091201715 4507254.590010401, 461271.56385885156 4507303.918307676, 461273.67536588735 4507318.460376316, 461286.2322009634 4507358.346460313, 461302.55653224624 4507403.197152592, 461365.2492823085 4507485.060388609, 461480.4983426857 4507548.512415529)')

实际场景中这些子线是数量不确定的列表，我希望将主线路分割成n+1段（n为短于主线路的子线数量），比如本例中要分成4段，但尝试的代码没得到预期结果：

line_list = [line_1, line_2, line_3]
diff_list = []
first_line_length = line_list[0].length

for line in line_list:
    line_length = line.length

    if line_length != first_line_length:
        diff = main_line.symmetric_difference(line)
        diff_list.append(diff)

fig, ax = plt.subplots(figsize=(10, 10))
ax.set_xlabel('X coordinate', fontsize=15)
ax.set_ylabel('Y coordinate', fontsize=15)

plt.plot(*main_line.xy, label='Main Line', color='blue')

plt.plot(*line_1.parallel_offset(distance=5).xy, label='Line 1', color='green')
plt.plot(*line_2.parallel_offset(distance=10).xy, label='Line 2', color='red')
plt.plot(*line_3.parallel_offset(distance=15).xy, label='Line 3', color='violet')

plt.plot(*diff_list[0].parallel_offset(distance=-5).xy, label='Diff Line 1', color='green')
plt.plot(*diff_list[1].parallel_offset(distance=-10).xy, label='Diff Line 2', color='red')

plt.legend()

plt.show()

运行结果如下：

解决方案 #

核心思路：收集所有子线的终点（因子线均从主线路起点开始重叠），计算这些点在主线路上的投影距离，排序后用这些距离分割主线路，得到n+1段。

实现代码 #

from shapely import wkt, ops
import matplotlib.pyplot as plt

# 加载线路数据
main_line = wkt.loads('LINESTRING (461179.6655721677 4507148.788223281, 461217.56786209624 4507181.537033379, 461236.3280996226 4507194.537878151, 461241.7247760045 4507197.640095252, 461258.8379542616 4507210.660701941, 461261.9432857035 4507219.791508417, 461270.90091201715 4507254.590010401, 461271.56385885156 4507303.918307676, 461273.67536588735 4507318.460376316, 461286.2322009634 4507358.346460313, 461302.55653224624 4507403.197152592, 461365.2492823085 4507485.060388609, 461480.4983426857 4507548.512415529, 461580.7367309019 4507618.493483591)')
line_1 = wkt.loads('LINESTRING (461179.6655721677 4507148.788223281, 461217.56786209624 4507181.537033379, 461236.3280996226 4507194.537878151, 461241.7247760045 4507197.640095252, 461258.8379542616 4507210.660701941, 461261.9432857035 4507219.791508417, 461270.90091201715 4507254.590010401, 461271.56385885156 4507303.918307676, 461273.67536588735 4507318.460376316, 461286.2322009634 4507358.346460313, 461302.55653224624 4507403.197152592)')
line_2 = wkt.loads('LINESTRING (461179.6655721677 4507148.788223281, 461217.56786209624 4507181.537033379, 461236.3280996226 4507194.537878151, 461241.7247760045 4507197.640095252, 461258.8379542616 4507210.660701941, 461261.9432857035 4507219.791508417, 461270.90091201715 4507254.590010401, 461271.56385885156 4507303.918307676, 461273.67536588735 4507318.460376316, 461286.2322009634 4507358.346460313, 461302.55653224624 4507403.197152592, 461365.2492823085 4507485.060388609)')
line_3 = wkt.loads('LINESTRING (461179.6655721677 4507148.788223281, 461217.56786209624 4507181.537033379, 461236.3280996226 4507194.537878151, 461241.7247760045 4507197.640095252, 461258.8379542616 4507210.660701941, 46