skills/geopandas/SKILL.md
Use GeoPandas for planar vector data represented as pandas-like GeoSeries and
GeoDataFrame objects. This skill targets stable GeoPandas 1.1.4 (released
2026-06-26), not the unreleased 1.2 documentation.
GeoPandas 1.1.4 requires Python 3.10+; its tagged source requires NumPy >=1.24,
pandas >=2.0, Shapely >=2.0, pyproj >=3.5, pyogrio >=0.7.2, and packaging.
This exact Python 3.12 snapshot was smoke-tested on 2026-07-23:
uv venv --python 3.12
uv pip install \
"geopandas==1.1.4" \
"numpy==2.5.1" \
"pandas==3.0.5" \
"shapely==2.1.2" \
"pyproj==3.7.2" \
"pyogrio==0.13.0" \
"pyarrow==25.0.0" \
"packaging==26.2"
Keep optional plotting and PostGIS packages pinned in the project lock as well. Do not mix binary geospatial packages from incompatible package channels.
/vsi* path, archive, or
geocode an address. Obtain explicit approval, validate provenance and hashes,
then stage an unpacked local file in an isolated workspace.GEOPANDAS_POSTGIS_PASSWORD; use a
secret manager or scoped environment variable. Never embed a password in a
URL or source, print an engine/URL, or dump the environment.Apply these gates before trusting a result:
None is missing; an empty Shapely geometry is real.set_crs() assigns metadata;
to_crs() transforms coordinates. Never guess a CRS from coordinate ranges.merge, sjoin, or sjoin_nearest; audit unmatched and
multiplied rows afterward.GeoPandas stores CRS as pyproj.CRS. Coordinate arrays use traditional GIS
(x, y) order, while authority definitions can advertise latitude-first axes.
Use Transformer(..., always_xy=True) for explicit coordinate-array pipelines,
and record that choice.
to_crs() transforms vertices and assumes each segment is straight in the
source CRS; it does not transform geodesic arcs. Geometries crossing ±180° or a
projection boundary can be badly wrapped. Detect crossings, split/unwrap and
densify in a documented geographic representation, transform parts, then
validate. Do not use Web Mercator as a general measurement CRS.
crs = gdf.crs # a pyproj.CRS when present
if crs is None or crs.is_geographic:
raise ValueError("Choose a justified projected CRS before planar measurement")
unit_names = [axis.unit_name for axis in crs.axis_info]
areas = gdf.geometry.area # square CRS units, not automatically square metres
See CRS management.
GeoDataFrame can hold multiple geometry columns, each with CRS metadata,
but only active_geometry_name drives frame-level spatial operations.GeoSeries methods are row-wise and align by index by default. Use
align=False only when positional pairing is explicitly intended and lengths
and order were verified.See data structures.
Use is_valid and redacted is_valid_reason() categories before
make_valid(method="linework"|"structure", keep_collapsed=...). Repair can
change geometry type or dimension; retain the original and compare counts,
area, types, empties, and collapsed parts.
set_precision(grid_size, mode=...) uses CRS units and may remove duplicate
vertices or collapse features. union_all(method="unary", grid_size=...) is the
robust default. Use coverage only after is_valid_coverage() proves
non-overlap and edge matching; use disjoint_subset with Shapely >=2.1 when its
partitioning assumption is useful.
See geometric operations.
sjoin predicates are directional: left.within(right) is not
left.contains(right). intersects includes boundary contact; contains
excludes boundary-only points, while covers includes boundary points.predicate="dwithin" requires distance; scalar or per-left-row distances
are in CRS units. sjoin_nearest returns all equidistant nearest matches and
does not implement a k= parameter.overlay(..., make_valid=True) repairs invalid input but can change types;
keep_geom_type=None drops other types with a warning. Precision mismatch can
create slivers; quantify them rather than silently deleting them.clip dissolves the mask. Rectangle clipping is fast but possibly dirty and
may omit a line collapsed to a point; validate its output.dissolve combines groupby.agg with union_all; choose explicit attribute
aggregations and audit null group keys.See spatial analysis.
GeoPandas 1.x defaults to pyogrio. Driver availability and semantics come from the installed GDAL, not GeoPandas alone. Prefer local GeoPackage for general interchange and WKB GeoParquet for columnar interoperability.
GeoParquet defaults to stable schema 1.0.0. Native GeoArrow encodings and bbox
covering require schema 1.1.0 and remain less interoperable. A missing GeoParquet
crs key means OGC:CRS84; explicit crs: null means unknown—do not conflate
them. Reopen and validate every export.
Use parameterized SQL and a SQLAlchemy Engine/Connection for PostGIS.
if_exists="replace" is destructive; default to "fail" and use a transaction.
See data I/O.
For code moving from GeoPandas 0.14 or earlier:
engine=
explicitly and test schema, empty, datetime, encoding, and append behavior.sjoin(op=...) with predicate=, sindex.query_bulk() with
sindex.query(), unary_union with union_all(), and
GeometryArray.data with to_numpy()/np.asarray.read_file(include_fields=...|ignore_fields=...) with columns=.
Use schema_version=, not the removed GeoParquet version= compatibility.geopandas.datasets, internal geopandas.io.* entry
points, plot axes/colormap, or set-operation operators.explode() now defaults index_parts=False; a named Series passed to
set_geometry() supplies the new active-column name; a named right index can
replace index_right in sjoin output..crs to override metadata or rely on deprecated
set_geometry(drop=...); use explicit set_crs() and rename/drop steps.=3.5. Version 1.1.2 fixed SQL injection through a PostGIS geometry-column name; the pinned 1.1.4 includes that fix.
Maps are analytical outputs: label units, classification method, missing data,
normalization denominator, and date. explore() can expose every attribute in
tooltips/popups and contact tile/CDN servers; generalize first and use
tiles=None, tooltip=False, and popup=False for a local draft.
See visualization.
All helpers are deterministic, reject network/archive paths, bound input bytes
and feature counts, keep imports lazy so --help is dependency-free, and emit
JSON without coordinates or record identifiers.
| CLI | Purpose |
|---|---|
scripts/vector_inventory.py | Redacted local vector/GeoParquet technical inventory |
scripts/crs_reprojection_plan.py | CRS units, axes, candidate transform and antimeridian plan |
scripts/geometry_validity_report.py | Dry-run validity audit; optional repair to a new GeoPackage |
scripts/spatial_join_audit.py | Predicate semantics, duplicate IDs and join cardinality |
scripts/export_plan.py | Non-executing vector/GeoParquet export contract |
scripts/sensitive_coordinates_checklist.py | Privacy/generalization release gate |
python skills/geopandas/scripts/vector_inventory.py --help
python skills/geopandas/scripts/crs_reprojection_plan.py \
--source-crs EPSG:4326 --target-crs EPSG:32631
python skills/geopandas/scripts/geometry_validity_report.py data.gpkg
python skills/geopandas/scripts/spatial_join_audit.py points.gpkg zones.gpkg \
--predicate within --left-id point_id --right-id zone_id
python skills/geopandas/scripts/export_plan.py data.gpkg result.parquet \
--format geoparquet --schema-version 1.0.0 \
--stable-id-column feature_id --id-unique-verified
python skills/geopandas/scripts/sensitive_coordinates_checklist.py \
--public-output --precise-points --contains-addresses