ValueError: Input geometry segment overlaps with the splitter.

[forestbat]

I'm trying to use a MultiLineString to cut LineString like this:

from shapely.ops import split, nearest_points
min_lines = split(origin_line, multiline)

And wkt of origin_line and multiline is this:

>>>origin.wkt
LINESTRING (126.195833 44.1875, 126.189583 44.19375, 126.189583 44.202083, 126.19375 44.20625, 126.189583 44.210417, 126.189583 44.214583, 126.185417 44.21875, 126.185417 44.260417, 126.189583 44.264583, 126.189583 44.28125, 126.197917 44.289583, 126.197917 44.302083, 126.202083 44.30625, 126.202083 44.314583)

>>>multiline.wkt
'MULTILINESTRING ((126.21 44.192, 116.24146526527336 43.39933661460323), (126.21 44.19, 116.21652550797235 44.551202958449714), (126.1939 44.2064, 119.12283218813452 37.13533218813453))'

However it crashed:

  File "C:\Users\Administrator\IdeaProjects\station-simulator\dijkstra_conda\ig_path.py", line 104, in find_edge_nodes
    geom_array, new_geom_array, index_geom_array = line_min_dist(gpd_nodes_df, gpd_network_df)
                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Administrator\IdeaProjects\station-simulator\dijkstra_conda\ig_path.py", line 49, in line_min_dist
    min_lines = split(origin_line, multiline)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Administrator\IdeaProjects\hydrodata\venv\Lib\site-packages\shapely\ops.py", line 544, in split
    return GeometryCollection(split_func(geom, splitter))
                              ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Administrator\IdeaProjects\hydrodata\venv\Lib\site-packages\shapely\ops.py", line 409, in _split_line_with_line
    raise ValueError("Input geometry segment overlaps with the splitter.")
ValueError: Input geometry segment overlaps with the splitter.

So why this problem will happen and how to avoid it?

[mwtoews]

The problem is that one of the input geometry segments overlaps with the splitter, as the error message describes. Even if you isolate the one line that touches the input line (so they are both LineString types) you will still see this message.

assert origin_line.overlaps(multiline)
print([origin_line.overlaps(part) for part in multiline.geoms])
# [False, False, True]
assert origin_line.overlaps(multiline.geoms[2])
split(origin_line, multiline.geoms[2])
# ValueError: Input geometry segment overlaps with the splitter.

to fix the error, the line must intersect the line in a way that it can "cut" it, and no go parallel along with it. This is the current geometries, where blue is origin_line and red is multiline.geoms[2]:

you can see that the lines overlap in a way it cannot be used to split the blue line.