BUG: Missing _crs attribute when using sjoin on grouped gdf and latest version of pandas

[kdpenner]

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of geopandas.

• (optional) I have confirmed this bug exists on the main branch of geopandas.

---

Code Sample, a copy-pastable example

import geopandas as gpd
from geopandas import sjoin
from shapely.geometry import MultiPoint


pts = MultiPoint([[0, 0], [1, 1]])
polys = [_.buffer(0.1) for _ in pts.geoms]
gdf = gpd.GeoDataFrame(["a", "b"], geometry=polys)

df_close = gdf.groupby(0).apply(lambda x: sjoin(x, x, how="inner",
                                                predicate="overlaps"))

Problem description

Unsure if this is a pandas or a geopandas problem. With pandas 1.2.5, the MWE above works fine. With pandas 1.3.5, it fails; here's the traceback:

Traceback (most recent call last):
  File "/Users/kylepenner/Desktop/bug.py", line 10, in <module>
    df_close = gdf.groupby(0).apply(lambda x: sjoin(x, x, how="inner",
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/pandas/core/groupby/groupby.py", line 1275, in apply
    result = self._python_apply_general(f, self._selected_obj)
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/pandas/core/groupby/groupby.py", line 1309, in _python_apply_general
    keys, values, mutated = self.grouper.apply(f, data, self.axis)
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/pandas/core/groupby/ops.py", line 852, in apply
    res = f(group)
  File "/Users/kylepenner/Desktop/bug.py", line 10, in <lambda>
    df_close = gdf.groupby(0).apply(lambda x: sjoin(x, x, how="inner",
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/geopandas/tools/sjoin.py", line 122, in sjoin
    _basic_checks(left_df, right_df, how, lsuffix, rsuffix)
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/geopandas/tools/sjoin.py", line 165, in _basic_checks
    if not _check_crs(left_df, right_df):
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/geopandas/array.py", line 68, in _check_crs
    if not left.crs == right.crs:
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/pandas/core/generic.py", line 5487, in __getattr__
    return object.__getattribute__(self, name)
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/geopandas/geodataframe.py", line 408, in crs
    return self._crs
  File "/Users/kylepenner/miniconda3/envs/test2/lib/python3.10/site-packages/pandas/core/generic.py", line 5487, in __getattr__
    return object.__getattribute__(self, name)
AttributeError: 'GeoDataFrame' object has no attribute '_crs'

Expected Output

A GeoDataFrame.

Output of geopandas.show_versions()

SYSTEM INFO

python : 3.10.1 | packaged by conda-forge | (main, Dec 22 2021, 01:39:14) [Clang 11.1.0 ]
executable : /Users/kylepenner/miniconda3/envs/test2/bin/python
machine : macOS-11.6.2-x86_64-i386-64bit

GEOS, GDAL, PROJ INFO

GEOS : 3.10.1
GEOS lib : /Users/kylepenner/miniconda3/envs/test2/lib/libgeos_c.dylib
GDAL : 3.4.1
GDAL data dir: /Users/kylepenner/miniconda3/envs/test2/share/gdal
PROJ : 8.2.1
PROJ data dir: /Users/kylepenner/miniconda3/envs/test2/share/proj

PYTHON DEPENDENCIES

geopandas : 0.10.2
pandas : 1.3.5
fiona : 1.8.20
numpy : 1.22.0
shapely : 1.8.0
rtree : 0.9.7
pyproj : 3.3.0
matplotlib : 3.5.1
mapclassify: 2.4.3
geopy : None
psycopg2 : None
geoalchemy2: None
pyarrow : None
pygeos : None

[jorisvandenbossche]

@kdpenner thanks for the report!

I suppose this will probably a regression in pandas 1.2->1.3 rather than in geopandas. Potentially related to pandas-dev/pandas#40236