AttributeError: 'Series' (or DataFrame) object has no attribute 'to_crs' when using dask_geopandas to reproject to new CRS

[dluks]

Description

I am experiencing an issue when trying to reproject a dask_geopandas.GeoSeries or dask_geopandas.GeoDataFrame to a new CRS. The set_crs and to_crs methods return an AttributeError indicating that the Series or DataFrame object has no attribute set_crs or to_crs.

I'm guessing this has to do with the fact that the geometry was created using dask_geopandas.points_from_xy, though even when I compute the GeoDataFrame, save it to disk, and re-read it using dask_geopandas.read_parquet, the issue still persists.

Code to reproduce

import pandas as pd
import dask.dataframe as dd
import dask_geopandas as dgpd

df = pd.DataFrame(
    {
        "value": [1, 2, 3],
        "decimallatitude": [34.05, 36.16, 40.71],
        "decimallongitude": [-118.24, -115.15, -74.00],
    }
)

ddf = dd.from_pandas(df, npartitions=2)

geom = dgpd.points_from_xy(
    ddf, "decimallongitude", "decimallatitude", crs="EPSG:4326"
)

ddf["geometry"] = geom

ddf = dgpd.from_dask_dataframe(ddf[["value", "geometry"]])

geom = geom.to_crs("EPSG:6933")  # <-- returns AttributeError
ddf  = ddf.to_crs("EPSG:6933")  # <-- also returns AttributeError 

Error Message

The following error is raised when attempting to use to_crs on geom alone:

AttributeError: 'Series' object has no attribute 'to_crs'

And on ddf:

AttributeError: 'DataFrame' object has no attribute 'to_crs'

Expected Behavior

I expect the to_crs method to reproject either a dask_geopandas.GeoSeries or dask_geopandas.GeoDataFrame to the new CRS without raising an error.

System Information

python: 3.11
dask-geopandas: 0.3.1
dask: 2024.9.0
pandas: 2.2.2
OS: Ubuntu 22.04.4 LTS

[dluks]

Here's the full stack trace:

---------------------------------------------------------------------------
AttributeError                        	Traceback (most recent call last)
File ~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:470, in Expr.__getattr__(self, key)
	[469](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:469) try:
--> [470](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:470) 	return object.__getattribute__(self, key)
	[471](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:471) except AttributeError as err:

AttributeError: 'MapPartitions' object has no attribute 'set_crs'

During handling of the above exception, another exception occurred:

AttributeError                        	Traceback (most recent call last)
File ~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:620, in FrameBase.__getattr__(self, key)
	[617](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:617) try:
	[618](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:618) 	# Fall back to `expr` API
	[619](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:619) 	# (Making sure to convert to/from Expr)
--> [620](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:620) 	val = getattr(self.expr, key)
	[621](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:621) 	if callable(val):

File ~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:491, in Expr.__getattr__(self, key)
	[490](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:490) link = "https://github.com/dask-contrib/dask-expr/blob/main/README.md#api-coverage"
--> [491](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:491) raise AttributeError(
	[492](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:492) 	f"{err}\n\n"
	[493](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:493) 	"This often means that you are attempting to use an unsupported "
	[494](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:494) 	f"API function. Current API coverage is documented here: {link}."
	[495](/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_core.py:495) )

AttributeError: 'MapPartitions' object has no attribute 'set_crs'

This often means that you are attempting to use an unsupported API function. Current API coverage is documented here: https://github.com/dask-contrib/dask-expr/blob/main/README.md#api-coverage.

During handling of the above exception, another exception occurred:

AttributeError                        	Traceback (most recent call last)
Cell In[41], [line 1](vscode-notebook-cell:?execution_count=41&line=1)
----> [1](vscode-notebook-cell:?execution_count=41&line=1) ddf.set_crs(4326)

File ~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:3076, in DataFrame.__getattr__(self, key)
   [3073](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:3073) 	raise err
   [3074](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:3074) except AttributeError:
   [3075](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:3075) 	# Fall back to `BaseFrame.__getattr__`
-> [3076](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:3076) 	return super().__getattr__(key)

File ~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:626, in FrameBase.__getattr__(self, key)
	[623](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:623) 	return val
	[624](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:624) except AttributeError:
	[625](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:625) 	# Raise original error
--> [626](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:626) 	raise err

File ~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:615, in FrameBase.__getattr__(self, key)
	[612](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:612) def __getattr__(self, key):
	[613](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:613) 	try:
	[614](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:614)     	# Prioritize `FrameBase` attributes
--> [615](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:615)     	return object.__getattribute__(self, key)
	[616](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:616) 	except AttributeError as err:
	[617](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:617)     	try:
	[618](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:618)         	# Fall back to `expr` API
	[619](https://vscode-remote+ssh-002dremote-002bpylos.vscode-resource.vscode-cdn.net/path/to/proj/~/miniforge3/envs/traits-py311/lib/python3.11/site-packages/dask_expr/_collection.py:619)         	# (Making sure to convert to/from Expr)

AttributeError: 'DataFrame' object has no attribute 'set_crs'

[TomAugspurger]

Thanks for the report. Looks like we just forgot to pass the crs through at

dask-geopandas/dask_geopandas/expr.py

Lines 912 to 914 in 33e2af8

	return df.map_partitions(
	func, x, y, z, meta=geopandas.GeoSeries(), token="points_from_xy"
	)

. This diff seems to fix it

diff --git a/dask_geopandas/core.py b/dask_geopandas/core.py
index b448319..4ef455c 100644
--- a/dask_geopandas/core.py
+++ b/dask_geopandas/core.py
@@ -878,7 +878,7 @@ def points_from_xy(df, x="x", y="y", z="z", crs=None):
         )
 
     return df.map_partitions(
-        func, x, y, z, meta=geopandas.GeoSeries(), token="points_from_xy"
+        func, x, y, z, meta=geopandas.GeoSeries(crs=crs), token="points_from_xy"
     )
 
 
diff --git a/dask_geopandas/expr.py b/dask_geopandas/expr.py
index a14e8bc..dcdafa8 100644
--- a/dask_geopandas/expr.py
+++ b/dask_geopandas/expr.py
@@ -910,7 +910,7 @@ def points_from_xy(df, x="x", y="y", z="z", crs=None):
         )
 
     return df.map_partitions(
-        func, x, y, z, meta=geopandas.GeoSeries(), token="points_from_xy"
+        func, x, y, z, meta=geopandas.GeoSeries(crs=crs), token="points_from_xy"
     )
 

Let us know if you're interested in making a PR with that change and a test.