How to get the endpoint of a LineString in Shapely

Question

Linestring1 = LINESTRING (51.2176008 4.4177154, 51.21758 4.4178548, **51.2175729 4.4179023**, *51.21745162000732 4.41871738126533*)
Linestring2 = LINESTRING (*51.21745162000732 4.41871738126533*, **51.2174025 4.4190475**, 51.217338 4.4194807, 51.2172511 4.4200562, 51.2172411 4.4201077, 51.2172246 4.4201654, 51.2172067 4.420205, 51.2171806 4.4202355, 51.2171074 4.4202929, 51.2170063 4.4203409, 51.2169564 4.4203641, 51.2168076 4.4204243, 51.2166588 4.4204833, 51.2159018 4.420431, 51.2154117 4.4203843)

Considering these two linestrings were cut from a bigger linestring, how to get the endpoint of a LineString?

- Point(51.21745162000732 4.41871738126533) removed

- The new last element of linestring 1 = “ 51.2175729 4.4179023

- The new first element of linestring 2 = “ 51.2174025 4.4190475

In short, I want to get the new last value of the first part (linestring1) and the new first value of the second part (linestring2), but without the point where I cut them. How can I make this work?

Answer 1

To get endpoints of a LineString, you just need to access its boundary property:

from shapely.geometry import LineString

line = LineString([(0, 0), (1, 1), (2, 2)])
endpoints = line.boundary
print(endpoints)
# MULTIPOINT (0 0, 2 2)
first, last = line.boundary
print(first, last)
# POINT (0 0) POINT (2 2)

Alternatively, you can get the first and the last points from the coords cordinate sequence:

from shapely.geometry import Point
first = Point(line.coords[0])
last = Point(line.coords[-1])
print(first, last)
# POINT (0 0) POINT (2 2)

---

In your specific case, though, as you want to remove the last point of the first line, and the first point of the second line, and only after that get the endpoints, you should construct new LineString objects first using the same coords property:

from shapely.wkt import loads

first_line = loads("LINESTRING (51.2176008 4.4177154, 51.21758 4.4178548, 51.2175729 4.4179023, 51.21745162000732 4.41871738126533)")
second_line = loads("LINESTRING (51.21745162000732 4.41871738126533, 51.2174025 4.4190475, 51.217338 4.4194807, 51.2172511 4.4200562, 51.2172411 4.4201077, 51.2172246 4.4201654, 51.2172067 4.420205, 51.2171806 4.4202355, 51.2171074 4.4202929, 51.2170063 4.4203409, 51.2169564 4.4203641, 51.2168076 4.4204243, 51.2166588 4.4204833, 51.2159018 4.420431, 51.2154117 4.4203843)")
first_line = LineString(first_line.coords[:-1])
second_line = LineString(second_line.coords[1:])
print(first_line.boundary[1], second_line.boundary[0])
# POINT (51.2175729 4.4179023) POINT (51.2174025 4.4190475)

Answer 2

Similar to Georgy's solution, you can get their coords by unpacking the one you want and ignoring the rest using *_.

from shapely.geometry import LineString

linestring1 = LineString([(51.2176008, 4.4177154), (51.21758, 4.4178548),
                         (51.2175729, 4.4179023),
                         (51.21745162000732, 4.41871738126533)])
linestring2 = LineString([(51.21745162000732, 4.41871738126533),
                         (51.2174025, 4.4190475), (51.217338, 4.4194807),
                         (51.2172511, 4.4200562), (51.2172411, 4.4201077),
                         (51.2172246, 4.4201654), (51.2172067, 4.420205),
                         (51.2171806, 4.4202355), (51.2171074, 4.4202929),
                         (51.2170063, 4.4203409), (51.2169564, 4.4203641),
                         (51.2168076, 4.4204243), (51.2166588, 4.4204833),
                         (51.2159018, 4.420431), (51.2154117, 4.4203843)])

*_, last_new_1, last_1 = linestring1.coords
first_2, first_new_2, *_ = linestring2.coords

print(last_new_1)
print(first_new_2)
# (51.2175729, 4.4179023)
# (51.2174025, 4.4190475)