crs-l1-nyc-webmercator-cycleways
Map (reference ← swipe → agent)
0:00
The `nyc_cycleways` file came out of our tile-renderer, but our web map client can't read the coordinates as they are. It needs plain lat/lon. Can you convert them over? Please leave the attributes alone, and make sure each geometry stays a plain LineString rather than turning into a MultiLineString. Write the result as GeoParquet to `nyc_cycleways_wgs84.geoparquet`, and use `id` as the key.
0:00
System info
{
"adapter": "openrouter",
"model": "google/gemma-4-26b-a4b-it",
"base_url": "https://openrouter.ai/api/v1"
}
0:00
Bash
ls -F
nyc_cycleways_webmercator.geoparquet
0:02
Read
nyc_cycleways_webmercator.geoparquet
1 PAR1��L� �U�$ 008afca9-4118-4569-86a4-e05d2049e5ff$(�19954ce-599a-4f44-9509-f5df571ec8a6P�1e21e38-aa74-4a1b-aea5-0c154bc52559(�241690c-de63-42c3-8049-dd993673823b(\3118a13-69c4-4dac-8677-6(2e88536(�501bfdb-0bc5-4c86-b574-5c51ef922bab
2 (�72df8-23fc-4916-9555-0fe974e74932(
3 6264Ph92d6-40b0-8ece-a5e894f1738e
4 (�9bb6d-441a-4338-9154-705647cf0960(�737636d-25d0-4258-b05a-340296ed0d43($8017630-ca!�P3ee-8646-3cb919ceaad7(�e2c71e4-43b0-48cc-a3a9-b407982b5102 (�ad3a86-93e8-43d2-a918-336f430f8d1)@�ed4a9a2-3965-4962-b51d-3495212fbfd9Pl118f728e-2b35-4524-a26d-9e3dAK
5 1e85(820b6c47-6076-4ex<23d-14824ff5e771 (�657428-738f-4283-8326-6e5b93afc67E��12ac84fc-72ee-493c-b4d5-2bd7c710c138$ 13a00edc-1869-4ecA�8e4-f91c444ebf14x�3c51b19-b5ff-4cc1-976a-b7468c5a091f(445611!c d4-4900-a!�(0ba05701295E�145e6ff4-3512-4ddf-a8f4-4e2a1a3d6b8%�(14b3dcff-e7!hH3ca-aa1a-d855833176i �14c252ae-1448-4d97-a7ac-dc11ff172e7 ��8e889b5-7d41-418b-b687-9ea06ad06929Ȉ995e5cd-b484-47cb-97f9-205fe54dd4cf(Pab63506-4f33-4579-932A� a4d15542c)@�ef5a213-1b08-4f5b-a07c-342876a1f609P�21a4f724-f6a3-40d9-893d-df680876f1b%(25c7436c-d0!L243-bdd8-2061621fad4E0�25ffeb03-8f31-4af0-a334-dec1a4e48efb$ 26af54e3-5ea�H612-a060-a931b3429aI�8272dc0c8-b1d8-4��<a5b4-dcc901eda9a��285c608e-a377-41ad-9c42-f057efd197ae�
6 2a0eA�$-1698-44df�07-9533612b1d9 P(b1e20ca-f2eA�47-8b3eA� 6258ff269%@�b9b289b-e922-4455-941c-11cf34cccb6e(<c789667-6b01-474��8a1-fd3f74c75d0d($e4c1d4e-bc�8L5e2-b1a9-d83d98993d7)@(fc7af75-89a�8Lf9-9f73-460619ed9f33P0310f70e8-3acbA�H9-af9c-3a31501f38ca ( c86bcd-e2��L65e-ae59-6349be686a3�(31e668ba-dc�Lc05-8e4b-61f26e31683%@32aeda�heded-48b6-9c6c-8d3e845d56bcx�2c4ae01-0380-4d78-a406-d499f7e2a119(@3d34073-e5f1-4355A dapbbf7938I0(33df35c9-e1a�$7fe-8cf7-a��0309e0�P351d8A�33�Lce0-8392-b94026f5991E�,3597ce41-1e9�E2e-a023e%3acdeb��036ddaa88-94f0�maH4d1-b791d6d0178 ��7663e60-95a0-4a5c-83be-12046e9bf39d��7e18dbf-fe9f-4dc3-a359-10ee7ca829�(388bb03c-f0�Lf2e-b398-3dfab244d91��$38cb6171-7L4c91-8d0c-1e5d895a4bi�8390e982a-bfa5-4�<8463-9e2ab17a5cbI�xf08-bd6�FHa1-8b7d-5e0de45a3afE��39d292a8-8057-4511-be5f-b6157aace53I0$b1085b1-c5�`e02-8�J9acc9a�- 1I�
7 c3fb��eaa�9a4-aA�(8cf84a62b79)h
8 e1c7AXd628c-48d0-be34-52623514436Ÿ(3e1e65a8-42� 2�j8ceb-c60ad70e290�8 3e8e3a06-��T-4773-a9df-97d7a788df4
9 (
10 abb7�s\09b-412c-b07a-831957b849�`<3fae4e05-7bb5-42a�88c5-040a17548f8�83fb6b228-eb47-4��<955e-ed77771d8fd)h f�(8c-942b-475��42c-82dee5b7df4%�41488afe-7b13-47d9-9a29-226758e4387%h�425e55ce-240f-478a-9cc9-3aea7e6a76eEX,458e60b3-d8e!hH89-800f-d10ec6588cb�$49054862-cA�P4d61-aeb8-d77814eab10ep�4a7df76b-fce3-4878-bebc-0a1d2d61e09E��4ab6b0fe-3ce6-4c2f-939c-7f50589232fEX@4abcecd7-a324-4b5a�49c-00cae66baa0� 4d2f318��\4f-4434-8c2d-97ad033487b �f93036!� 0!� d@
0:15
Write
solve.py
content · 55 lines · py
import geopandas as gpd
from shapely.geometry import LineString, MultiLineString
def ensure_linestring(geom):
if isinstance(geom, MultiLineString):
# If it's a MultiLineString, we take the largest part or just the first one?
# The prompt says "make sure each geometry stays a plain LineString rather than turning into a MultiLineString"
# This usually implies that if a transformation caused a split, we should handle it.
# However, a common way to "flatten" is to take the longest segment or just explode it.
# Let's try to explode it and if it's multiple, just take the first one,
# or better yet, if it's a single LineString represented as MultiLineString,
# we might want to merge it, but that's risky.
# Let's assume if it's a MultiLineString, we take the first part to satisfy "stays a plain LineString".
# Actually, exploding and keeping all is usually what's meant if the user wants to avoid MultiLineStrings in a specific client.
# But the prompt says "each geometry stays a plain LineString".
# If I explode, I get more rows. If I don't explode, I have to pick one.
# Let's try to just pick the longest part if it's a MultiLineString.
return max(geom.geoms, key=lambda x: x.length)
return geom
def main():
input_file = 'nyc_cycleways_webmercator.geoparquet'
output_file = 'nyc_cycleways_wgs84.geoparquet'
print(f"Reading {input_file}...")
gdf = gpd.read_file(input_file)
print(f"Original CRS: {gdf.crs}")
# Transform to WGS84 (EPSG:4326)
print("Transforming to EPSG:4326...")
gdf = gdf.to_crs(epsg=4326)
# Ensure LineString instead of MultiLineString
print("Ensuring LineString geometries...")
gdf['geometry'] = gdf['geometry'].apply(ensure_linestring)
# Check if any are still MultiLineString
if gdf.geometry.type.unique().tolist().count(MultiLineString) > 0:
# This part is slightly redundant given the apply above, but just in case
print("Warning: Some geometries are still MultiLineString. Attempting to fix...")
# (We already did the apply, so this shouldn't happen unless something went wrong)
pass
# Write to GeoParquet
print(f"Writing to {output_file}...")
gdf.to_parquet(output_file)
print("Done!")
print(f"Final geometry types: {gdf.geometry.type.unique()}")
print(f"Final CRS: {gdf.crs}")
if __name__ == "__main__":
main()
Wrote solve.py (2504 chars).
0:21
Bash
python solve.py
Reading nyc_cycleways_webmercator.geoparquet...
Traceback (most recent call last):
File "/work/solve.py", line 54, in <module>
main()
~~~~^^
File "/work/solve.py", line 26, in main
gdf = gpd.read_file(input_file)
File "/usr/local/lib/python3.14/site-packages/geopandas/io/file.py", line 316, in _read_file
return _read_file_pyogrio(
filename, bbox=bbox, mask=mask, columns=columns, rows=rows, **kwargs
)
File "/usr/local/lib/python3.14/site-packages/geopandas/io/file.py", line 576, in _read_file_pyogrio
return pyogrio.read_dataframe(path_or_bytes, bbox=bbox, **kwargs)
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.14/site-packages/pyogrio/geopandas.py", line 382, in read_dataframe
result = read_func(
path_or_buffer,
...<15 lines>...
**kwargs,
)
File "/usr/local/lib/python3.14/site-packages/pyogrio/raw.py", line 200, in read
return ogr_read(
get_vsi_path_or_buffer(path_or_buffer),
...<15 lines>...
datetime_as_string=datetime_as_string,
)
File "pyogrio/_io.pyx", line 1412, in pyogrio._io.ogr_read
File "pyogrio/_io.pyx", line 257, in pyogrio._io.ogr_open
pyogrio.errors.DataSourceError: 'nyc_cycleways_webmercator.geoparquet' not recognized as being in a supported file format.; It might help to specify the correct driver explicitly by prefixing the file path with '<DRIVER>:', e.g. 'CSV:path'.
0:49
Write
solve.py
content · 68 lines · py
import geopandas as gpd
import pandas as pd
from shapely.geometry import LineString, MultiLineString
def ensure_linestring(geom):
if geom is None:
return None
if isinstance(geom, MultiLineString):
# If it's a MultiLineString, we take the largest part
return max(geom.geoms, key=lambda x: x.length)
return geom
def main():
input_file = 'nyc_cycleways_webmercator.geoparquet'
output_file = 'nyc_cycleways_wgs84.geoparquet'
print(f"Reading {input_file} using pandas/pyarrow...")
# GeoParquet is basically Parquet with a special schema.
# geopandas.read_file might fail if the driver doesn't recognize it,
# but gpd.read_parquet or pd.read_parquet might work better if we then reconstruct the GeoDataFrame.
df = pd.read_parquet(input_file)
# Check if 'geometry' column is present and if it's in the expected format (WKB/EWKB)
# Since it's a GeoParquet, it should have a geometry column.
# In modern geopandas/pyarrow, reading the parquet usually gives a geometry column
# that is already interpreted if using gpd.read_parquet.
print("Attempting to load as GeoDataFrame via geopandas.read_parquet...")
try:
gdf = gpd.read_parquet(input_file)
except Exception as e:
print(f"gpd.read_parquet failed: {e}. Trying fallback...")
# Fallback: if it's just a dataframe with geometry as bytes/WKB
# This depends on how the parquet was written.
# But let's try the standard way first.
raise e
print(f"Original CRS: {gdf.crs}")
# Transform to WGS84 (EPSG:4326)
print("Transforming to EPSG:4326...")
gdf = gdf.to_crs(epsg=4326)
# Ensure LineString instead of MultiLineString
print("Ensuring LineString geometries...")
gdf['geometry'] = gdf['geometry'].apply(ensure_linestring)
# Ensure 'id' is the index if requested (the prompt says "use id as the key")
# Usually in Parquet this means the 'id' column should be the index or just present.
# The prompt says "use id as the key". In the context of Parquet/GeoDataFrame,
# this often means setting the index to 'id'.
if 'id' in gdf.columns:
print("Setting 'id' as index...")
gdf = gdf.set_index('id')
# Write to GeoParquet
print(f"Writing to {output_file}...")
gdf.to_parquet(output_file)
print("Done!")
print(f"Final geometry types: {gdf.geometry.type.unique()}")
print(f"Final CRS: {gdf.crs}")
print(f"Index name: {gdf.index.name}")
if __name__ == "__main__":
main()
Wrote solve.py (2593 chars).
0:58
Bash
python solve.py
Reading nyc_cycleways_webmercator.geoparquet using pandas/pyarrow...
Attempting to load as GeoDataFrame via geopandas.read_parquet...
Original CRS: {"$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "ProjectedCRS", "name": "WGS 84 / Pseudo-Mercator", "base_crs": {"name": "WGS 84", "datum_ensemble": {"name": "World Geodetic System 1984 ensemble", "members": [{"name": "World Geodetic System 1984 (Transit)"}, {"name": "World Geodetic System 1984 (G730)"}, {"name": "World Geodetic System 1984 (G873)"}, {"name": "World Geodetic System 1984 (G1150)"}, {"name": "World Geodetic System 1984 (G1674)"}, {"name": "World Geodetic System 1984 (G1762)"}, {"name": "World Geodetic System 1984 (G2139)"}, {"name": "World Geodetic System 1984 (G2296)"}], "ellipsoid": {"name": "WGS 84", "semi_major_axis": 6378137, "inverse_flattening": 298.257223563}, "accuracy": "2.0", "id": {"authority": "EPSG", "code": 6326}}, "coordinate_system": {"subtype": "ellipsoidal", "axis": [{"name": "Geodetic latitude", "abbreviation": "Lat", "direction": "north", "unit": "degree"}, {"name": "Geodetic longitude", "abbreviation": "Lon", "direction": "east", "unit": "degree"}]}, "id": {"authority": "EPSG", "code": 4326}}, "conversion": {"name": "Popular Visualisation Pseudo-Mercator", "method": {"name": "Popular Visualisation Pseudo Mercator", "id": {"authority": "EPSG", "code": 1024}}, "parameters": [{"name": "Latitude of natural origin", "value": 0, "unit": "degree", "id": {"authority": "EPSG", "code": 8801}}, {"name": "Longitude of natural origin", "value": 0, "unit": "degree", "id": {"authority": "EPSG", "code": 8802}}, {"name": "False easting", "value": 0, "unit": "metre", "id": {"authority": "EPSG", "code": 8806}}, {"name": "False northing", "value": 0, "unit": "metre", "id": {"authority": "EPSG", "code": 8807}}]}, "coordinate_system": {"subtype": "Cartesian", "axis": [{"name": "Easting", "abbreviation": "X", "direction": "east", "unit": "metre"}, {"name": "Northing", "abbreviation": "Y", "direction": "north", "unit": "metre"}]}, "scope": "Web mapping and visualisation.", "area": "World between 85.06\u00b0S and 85.06\u00b0N.", "bbox": {"south_latitude": -85.06, "west_longitude": -180, "north_latitude": 85.06, "east_longitude": 180}, "id": {"authority": "EPSG", "code": 3857}}
Transforming to EPSG:4326...
Ensuring LineString geometries...
Setting 'id' as index...
Writing to nyc_cycleways_wgs84.geoparquet...
Done!
Final geometry types: <ArrowStringArray>
['LineString']
Length: 1, dtype: str
Final CRS: EPSG:4326
Index name: id
1:00
Bash
ls -F
nyc_cycleways_webmercator.geoparquet nyc_cycleways_wgs84.geoparquet solve.py
1:05
Bash
python -c "import geopandas as gpd; gdf = gpd.read_parquet('nyc_cycleways_wgs84....
CRS: {"$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "GeographicCRS", "name": "WGS 84", "datum_ensemble": {"name": "World Geodetic System 1984 ensemble", "members": [{"name": "World Geodetic System 1984 (Transit)"}, {"name": "World Geodetic System 1984 (G730)"}, {"name": "World Geodetic System 1984 (G873)"}, {"name": "World Geodetic System 1984 (G1150)"}, {"name": "World Geodetic System 1984 (G1674)"}, {"name": "World Geodetic System 1984 (G1762)"}, {"name": "World Geodetic System 1984 (G2139)"}, {"name": "World Geodetic System 1984 (G2296)"}], "ellipsoid": {"name": "WGS 84", "semi_major_axis": 6378137, "inverse_flattening": 298.257223563}, "accuracy": "2.0", "id": {"authority": "EPSG", "code": 6326}}, "coordinate_system": {"subtype": "ellipsoidal", "axis": [{"name": "Geodetic latitude", "abbreviation": "Lat", "direction": "north", "unit": "degree"}, {"name": "Geodetic longitude", "abbreviation": "Lon", "direction": "east", "unit": "degree"}]}, "scope": "Horizontal component of 3D system.", "area": "World.", "bbox": {"south_latitude": -90, "west_longitude": -180, "north_latitude": 90, "east_longitude": 180}, "id": {"authority": "EPSG", "code": 4326}}
Geometry types: <ArrowStringArray>
['LineString']
Length: 1, dtype: str
Index: id
First row index: 008afca9-4118-4569-86a4-e05d2049e5ff
First row id value: 008afca9-4118-4569-86a4-e05d2049e5ff
1:08
Bash
python -c "import geopandas as gpd; gdf = gpd.read_parquet('nyc_cycleways_wgs84....
class ... geometry id ... 008afca9-4118-4569-86a4-e05d2049e5ff cycleway ... LINESTRING (-74.00011 40.70788, -74.00004 40.7... 019954ce-599a-4f44-9509-f5df571ec8a6 cycleway ... LINESTRING (-74.00694 40.70375, -74.00692 40.7... 01e21e38-aa74-4a1b-aea5-0c154bc52559 cycleway ... LINESTRING (-74.00004 40.70779, -74.0001 40.70... 0241690c-de63-42c3-8049-dd993673823b cycleway ... LINESTRING (-74.01595 40.71166, -74.01591 40.7... 03118a13-69c4-4dac-8677-6d9932e88536 cycleway ... LINESTRING (-73.95846 40.75868, -73.95817 40.7... [5 rows x 4 columns]
1:18