Why am I getting the error "EEException: List.map: Parameter 'list' is required." when converting GEE feature collection to geopandas df in python?

Question

I'm trying to get a df with tree cover loss by year by sector of the DRC using the gee python API. The output feature collection is finally what I want, but I keep getting the following error:


EEException: List.map: Parameter 'list' is required.

During handling of the above exception, another exception occurred:

Exception                                 Traceback (most recent call last)
<ipython-input-12-92980ec1d8af> in <cell line: 42>()
     40 # Map the function over the feature collection
     41 tree_change_over_time_fc = sectors_fc_nonlist.map(calculate_loss_for_feature)
---> 42 tree_change_over_time_fc_gdb = geemap.ee_to_pandas(tree_change_over_time_fc)
     43 
     44 # Print the result

/data/dataiku/dss_data/code-envs/python/geospatial/lib/python3.9/site-packages/geemap/common.py in ee_to_df(ee_object, col_names, sort_columns, **kwargs)
   8951         return df
   8952     except Exception as e:
-> 8953         raise Exception(e)
   8954 
   8955 

Exception: List.map: Parameter 'list' is required.

Here are my Sectors: https://code.earthengine.google.com/?asset=users/darcygray/DRC_sectors

#Read recipe inputs and convert sectors to a feature collection
hansenDataset = ee.Image('UMD/hansen/global_forest_change_2022_v1_10')
Sectors = dataiku.Dataset("Sectors_copy")

def convert_to_geometry(ewkt_string):
    return wkt.loads(ewkt_string)

df = Sectors.get_dataframe()
df = pd.DataFrame(df)
df['geometry'] = df['the_geom'].apply(convert_to_geometry)
gdf = gpd.GeoDataFrame(df, geometry='geometry')
gdf.crs = 'EPSG:4326'
gdf = gdf.iloc[:, 1:]
gdf = gdf.iloc[:10]
sectors_fc_nonlist = geemap.geopandas_to_ee(gdf)
# Define  loss calculation function
def calculate_loss_for_feature(sector):
    geometry = sector.geometry()
    sectorName = sector.get('NOM')
    
    # Reduce the region for the filtered feature
    lossByYear_sector = lossByYear.reduceRegion(
        reducer=ee.Reducer.sum().group(
            groupField=1,
            groupName='lossyear',
        ),
        geometry=geometry,
        scale=30,
        maxPixels=1e9
    )

    stats = ee.List(lossByYear.get('groups'))
    def format_element(el):
        d = ee.Dictionary(el)
        group = ee.Number(d.get('lossyear')).format("20%02d")
        return [group, d.get('sum')]

    stats_formatted = stats.map(format_element)
    stats_flattened = stats_formatted.flatten()
    return ee.Feature(None,{
        'SectorName': sectorName,
        'LossOverTime': stats_flattened}).setGeometry(sector.geometry())

#prep Image
lossImage = hansenDataset.select(['loss'])
lossAreaImage = lossImage.multiply(ee.Image.pixelArea())
lossYear = hansenDataset.select(['lossyear'])
lossByYear = lossAreaImage.addBands(lossYear)

# Map the function over the feature collection
tree_change_over_time_fc = sectors_fc_nonlist.map(calculate_loss_for_feature)
tree_change_over_time_fc_gdb = geemap.ee_to_pandas(tree_change_over_time_fc)

# Print the result
print(tree_change_over_time_fc.get('LossOverTime'))

user232059 · Accepted Answer · 2023-10-16 13:11:34Z

Okay I actually got it to work!

The issue was the ee.Dictionary that was being defined inside the function. I changd this to a list, and then I do the manipulation of format downstream.

Here's the updated function:

def calculate_loss_for_feature(sector):
    geometry = sector.geometry()
    sectorName = sector.get('NOM')

    # Reduce the region for the filtered feature
    lossByYear_sector = lossByYear.reduceRegion(
        reducer=ee.Reducer.sum().group(
            groupField=1,
            groupName='lossyear',
        ),
        geometry=geometry,
        scale=30,
        maxPixels=1e9
    )

    # Access the 'groups' from the reducer's output
    stats = ee.List(lossByYear_sector.get('groups'))

    # Create a dictionary to store the results
    feature_properties = {
        'SectorName': sectorName,
        'LossOverTime': stats
    }

    # Create a feature with properties
    feature = ee.Feature(geometry, feature_properties)

    return feature

Stack Exchange Network

Why am I getting the error "EEException: List.map: Parameter 'list' is required." when converting GEE feature collection to geopandas df in python?

1 Answer 1

Your Answer

Hot Network Questions

Why am I getting the error "EEException: List.map: Parameter 'list' is required." when converting GEE feature collection to geopandas df in python?

1 Answer 1

Your Answer

Sign up or log in

Post as a guest

Related

Hot Network Questions