GeoPandas Spatial Join Error: 'left_df' should be GeoDataFrame, got <class 'geopandas.geoseries.GeoSeries'

Question

I have a gdf with this characteristics:

gdf.info()

<class 'geopandas.geodataframe.GeoDataFrame'>
Int64Index: 405943 entries, 0 to 405942
Data columns (total 7 columns):
 #   Column    Non-Null Count   Dtype   
---  ------    --------------   -----   
 0   Mz        405943 non-null  object  
 1   Area_km2  405943 non-null  float64 
 2   UBIGEO    405943 non-null  object  
 3   IDPROV    405943 non-null  object  
 4   CCDD      405943 non-null  object  
 5   PobMz     405943 non-null  float64 
 6   geometry  405943 non-null  geometry
dtypes: float64(2), geometry(1), object(4)
memory usage: 40.9+ MB

So, first I want to get centroids from it:

cent=gdf.centroid
cent.head()

0    POINT (546598.404 8580848.223)
1    POINT (537595.600 8588489.910)
2    POINT (534681.734 8586405.771)
3    POINT (558020.684 8571566.834)
4    POINT (535966.243 8592514.133)
dtype: geometry

cent.crs

<Projected CRS: EPSG:32718>
Name: WGS 84 / UTM zone 18S
Axis Info [cartesian]:
- E[east]: Easting (metre)
- N[north]: Northing (metre)
Area of Use:
- name: Between 78°W and 72°W, southern hemisphere between 80°S and equator, onshore and offshore. Argentina. Brazil. Chile. Colombia. Ecuador. Peru.
- bounds: (-78.0, -80.0, -72.0, 0.0)
Coordinate Operation:
- name: UTM zone 18S
- method: Transverse Mercator
Datum: World Geodetic System 1984
- Ellipsoid: WGS 84
- Prime Meridian: Greenwich

But when I want to do a Spatial Join with another gdf:

trying = gpd.sjoin(cent, blocks, how="left")

I get this message:

ValueError: 'left_df' should be GeoDataFrame, got <class 'geopandas.geoseries.GeoSeries'>

How should be the proper code?

Answer 1

The result of the command cent=gdf.centroid is a GeoSerie and not a GeoDataFrame

gdf = gpd.read_file("poly.shp")
print(gdf)
   id                  geometry
0   1  POLYGON ((48.353 -92.936, 294.389 -111.862, 28...

cent=gdf.centroid
type(cent)
<class 'geopandas.geoseries.GeoSeries'>
 print(cent)
 0    POINT (158.530 -257.815)
dtype: geometry

Solution

cent  = gdf.copy() # copy GeoDataFrame
cent.geometry = gdf.geometry.centroid
type(cent)
 <class 'geopandas.geodataframe.GeoDataFrame'>
print(cent)
     id            geometry
 0    1  POINT (158.530 -257.815)