def test_read_file_layer(tmp_path):
df_points = geopandas.GeoDataFrame(
{
"col": [1, 2, 3, 4],
"geometry": geopandas.points_from_xy([1, 2, 3, 4], [2, 3, 4, 1]),
},
crs=4326,
)
df_polygons = geopandas.GeoDataFrame(
{
"col": [5, 6, 7, 8],
"geometry": [
Polygon([(random.random(), random.random()) for i in range(3)])
for _ in range(4)
],
},
crs=4326,
)
path = tmp_path / "test_layers.gpkg"
df_points.to_file(path, layer="points")
df_polygons.to_file(path, layer="polygons")
ddf_points = dask_geopandas.read_file(path, npartitions=2, layer="points")
assert_geodataframe_equal(ddf_points.compute(), df_points)
ddf_polygons = dask_geopandas.read_file(path,
npartitions=2,
layer="polygons")
assert_geodataframe_equal(ddf_polygons.compute(), df_polygons)
def test_read_file_columns():
path = geopandas.datasets.get_path("naturalearth_lowres")
df = geopandas.read_file(path)
# explicit column selection
result = dask_geopandas.read_file(path,
npartitions=4,
columns=["pop_est", "geometry"])
assert isinstance(result, dask_geopandas.GeoDataFrame)
assert result.npartitions == 4
assert result.crs == df.crs
assert len(result.columns) == 2
assert_geodataframe_equal(result.compute(), df[["pop_est", "geometry"]])
# only selecting non-geometry column
result = dask_geopandas.read_file(path, npartitions=4, columns=["pop_est"])
assert type(result) == dd.DataFrame
assert len(result.columns) == 1
assert result.npartitions == 4
assert_frame_equal(result.compute(), df[["pop_est"]])
# column selection through getitem
ddf = dask_geopandas.read_file(path, npartitions=4)
result = ddf[["pop_est", "geometry"]]
assert isinstance(result, dask_geopandas.GeoDataFrame)
assert result.npartitions == 4
assert result.crs == df.crs
assert_geodataframe_equal(result.compute(), df[["pop_est", "geometry"]])
# only select non-geometry column
result = ddf["pop_est"]
assert isinstance(result, dd.Series)
assert_series_equal(result.compute(), df["pop_est"])
# only select geometry column
result = ddf["geometry"]
assert isinstance(result, dask_geopandas.GeoSeries)
assert_geoseries_equal(result.compute(), df["geometry"])
def test_read_file():
path = geopandas.datasets.get_path("naturalearth_lowres")
df = geopandas.read_file(path)
result = dask_geopandas.read_file(path, npartitions=4)
assert isinstance(result, dask_geopandas.GeoDataFrame)
assert result.npartitions == 4
assert result.crs == df.crs
assert_geodataframe_equal(result.compute(), df)
result = dask_geopandas.read_file(path, chunksize=100)
assert isinstance(result, dask_geopandas.GeoDataFrame)
assert result.npartitions == 2
assert result.crs == df.crs
assert_geodataframe_equal(result.compute(), df)
msg = "Exactly one of npartitions and chunksize must be specified"
with pytest.raises(ValueError, match=msg):
dask_geopandas.read_file(path)
with pytest.raises(ValueError, match=msg):
dask_geopandas.read_file(path, npartitions=4, chunksize=100)
def test_read_file_index():
path = geopandas.datasets.get_path("naturalearth_lowres")
df = geopandas.read_file(path)
result = dask_geopandas.read_file(path, npartitions=4)
assert (result.index.compute() == pd.RangeIndex(0, len(df))).all()
def test_read_file_divisions():
path = geopandas.datasets.get_path("naturalearth_lowres")
result = dask_geopandas.read_file(path, npartitions=4)
assert result.known_divisions
assert result.index.divisions == (0, 45, 90, 135, 176)
assert result.divisions == (0, 45, 90, 135, 176)