Convert API code snippets from JS to Py (reducers).

PiperOrigin-RevId: 711481948

samples/python/guides/reducers011.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - Image reduce' section."""
+
+# [START earthengine__reducers011__image_reduce]
+# Load an image and select some bands of interest.
+image = ee.Image('LANDSAT/LC08/C02/T1/LC08_044034_20140318').select(
+    ['B4', 'B3', 'B2']
+)
+
+# Reduce the image to get a one-band maximum value image.
+max_value = image.reduce(ee.Reducer.max())
+
+# Display the result.
+m = geemap.Map()
+m.center_object(image, 10)
+m.add_layer(max_value, {'max': 13000}, 'Maximum value image')
+m
+# [END earthengine__reducers011__image_reduce]

samples/python/guides/reducers03.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - reduceRegions' section."""
+
+# [START earthengine__reducers03__reduce_regions]
+# Load input imagery: Landsat 7 5-year composite.
+image = ee.Image('LANDSAT/LE7_TOA_5YEAR/2008_2012')
+
+# Load a FeatureCollection of counties in Maine.
+maine_counties = ee.FeatureCollection('TIGER/2016/Counties').filter(
+    ee.Filter.eq('STATEFP', '23')
+)
+
+# Add reducer output to the Features in the collection.
+maine_means_features = image.reduceRegions(
+    collection=maine_counties, reducer=ee.Reducer.mean(), scale=30
+)
+
+# Print the first feature, to illustrate the result.
+display(ee.Feature(maine_means_features.first()).select(image.bandNames()))
+# [END earthengine__reducers03__reduce_regions]

samples/python/guides/reducers04.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - reduceNeighborhood' section."""
+
+# [START earthengine__reducers04__reduce_neighborhood]
+# Define a region in the redwood forest.
+redwoods = ee.Geometry.Rectangle(-124.0665, 41.0739, -123.934, 41.2029)
+
+# Load input NAIP imagery and build a mosaic.
+naip_collection = (
+    ee.ImageCollection('USDA/NAIP/DOQQ')
+    .filterBounds(redwoods)
+    .filterDate('2012-01-01', '2012-12-31')
+)
+naip = naip_collection.mosaic()
+
+# Compute NDVI from the NAIP imagery.
+naip_ndvi = naip.normalizedDifference(['N', 'R'])
+
+# Compute standard deviation (SD) as texture of the NDVI.
+texture = naip_ndvi.reduceNeighborhood(
+    reducer=ee.Reducer.stdDev(), kernel=ee.Kernel.circle(7)
+)
+
+# Display the results.
+m = geemap.Map()
+m.center_object(redwoods, 12)
+m.add_layer(naip, {}, 'NAIP input imagery')
+m.add_layer(
+    naip_ndvi, {'min': -1, 'max': 1, 'palette': ['FF0000', '00FF00']}, 'NDVI'
+)
+m.add_layer(texture, {'min': 0, 'max': 0.3}, 'SD of NDVI')
+m
+# [END earthengine__reducers04__reduce_neighborhood]

samples/python/guides/reducers06.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - FeatureCollection.reduceColumns' section."""
+
+# [START earthengine__reducers06__toy_reduce_columns]
+# Make a toy FeatureCollection.
+a_feature_collection = ee.FeatureCollection([
+    ee.Feature(None, {'foo': 1, 'weight': 1}),
+    ee.Feature(None, {'foo': 2, 'weight': 2}),
+    ee.Feature(None, {'foo': 3, 'weight': 3}),
+])
+
+# Compute a weighted mean and display it.
+display(
+    a_feature_collection.reduceColumns(
+        reducer=ee.Reducer.mean(), selectors=['foo'], weightSelectors=['weight']
+    )
+)
+# [END earthengine__reducers06__toy_reduce_columns]

samples/python/guides/reducers07.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - FeatureCollection.reduceColumns' section."""
+
+# [START earthengine__reducers07__reduce_columns]
+# Load US census data as a FeatureCollection.
+census = ee.FeatureCollection('TIGER/2010/Blocks')
+
+# Filter the collection to include only Benton County, OR.
+benton = census.filter(
+    ee.Filter.And(
+        ee.Filter.eq('statefp10', '41'), ee.Filter.eq('countyfp10', '003')
+    )
+)
+
+# Display Benton County census blocks.
+m = geemap.Map()
+m.set_center(-123.27, 44.57, 13)
+m.add_layer(benton)
+display(m)
+
+# Compute sums of the specified properties.
+properties = ['pop10', 'housing10']
+sums = benton.filter(ee.Filter.notNull(properties)).reduceColumns(
+    reducer=ee.Reducer.sum().repeat(2), selectors=properties
+)
+
+# Print the resultant Dictionary.
+display(sums)
+# [END earthengine__reducers07__reduce_columns]

samples/python/guides/reducers08.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - FeatureCollection.reduceToImage' section."""
+
+# [START earthengine__reducers08__reduce_to_image]
+# Load a collection of US counties.
+counties = ee.FeatureCollection('TIGER/2018/Counties')
+
+# Make an image out of the land area attribute.
+land_area_img = counties.filter(ee.Filter.notNull(['ALAND'])).reduceToImage(
+    properties=['ALAND'], reducer=ee.Reducer.first()
+)
+
+# Display the county land area image.
+m = geemap.Map()
+m.set_center(-99.976, 40.38, 5)
+m.add_layer(
+    land_area_img,
+    {
+        'min': 3e8,
+        'max': 1.5e10,
+        'palette': ['FCFDBF', 'FDAE78', 'EE605E', 'B63679', '711F81', '2C105C'],
+    },
+)
+m
+# [END earthengine__reducers08__reduce_to_image]

samples/python/guides/reducers09.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - Grouping' section."""
+
+# [START earthengine__reducers09__grouping_fc]
+# Load a collection of US census blocks.
+blocks = ee.FeatureCollection('TIGER/2010/Blocks')
+
+# Compute sums of the specified properties, grouped by state code.
+sums = blocks.filter(
+    ee.Filter.And(
+        ee.Filter.neq('pop10', None), ee.Filter.neq('housing10', None)
+    )
+).reduceColumns(
+    selectors=['pop10', 'housing10', 'statefp10'],
+    reducer=ee.Reducer.sum()
+    .repeat(2)
+    .group(groupField=2, groupName='state-code'),
+)
+
+# Print the resultant Dictionary.
+display(sums)
+# [END earthengine__reducers09__grouping_fc]

samples/python/guides/reducers10.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - Grouping' section."""
+
+# [START earthengine__reducers10__grouping_image]
+# Load a region representing the United States
+region = ee.FeatureCollection('USDOS/LSIB_SIMPLE/2017').filter(
+    ee.Filter.eq('country_na', 'United States')
+)
+
+# Load MODIS land cover categories in 2001.
+landcover = ee.Image('MODIS/051/MCD12Q1/2001_01_01').select(
+    # Select the IGBP classification band.
+    'Land_Cover_Type_1'
+)
+
+# Load nightlights image inputs.
+nl_2001 = ee.Image('NOAA/DMSP-OLS/NIGHTTIME_LIGHTS/F152001').select(
+    'stable_lights'
+)
+nl_2012 = ee.Image('NOAA/DMSP-OLS/NIGHTTIME_LIGHTS/F182012').select(
+    'stable_lights'
+)
+
+# Compute the nightlights decadal difference, add land cover codes.
+nl_diff = nl_2012.subtract(nl_2001).addBands(landcover)
+
+# Grouped a mean reducer: change of nightlights by land cover category.
+means = nl_diff.reduceRegion(
+    reducer=ee.Reducer.mean().group(groupField=1, groupName='code'),
+    geometry=region.geometry(),
+    scale=1000,
+    maxPixels=1e8,
+)
+
+# Print the resultant Dictionary.
+display(means)
+# [END earthengine__reducers10__grouping_image]

samples/python/guides/reducers11.py

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+# Copyright 2024 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Earth Engine Developer's Guide examples from 'Reducers - unweighted' section."""
+
+# [START earthengine__reducers11__unweighted]
+# Load a Landsat 8 input image.
+image = ee.Image('LANDSAT/LC08/C02/T1/LC08_044034_20140318')
+
+# Create an arbitrary region.
+geometry = ee.Geometry.Rectangle(-122.496, 37.532, -121.554, 37.538)
+
+# Make an NDWI image.  It will have one band named 'nd'.
+ndwi = image.normalizedDifference(['B3', 'B5'])
+
+# Compute the weighted mean of the NDWI image clipped to the region.
+weighted = (
+    ndwi.clip(geometry)
+    .reduceRegion(reducer=ee.Reducer.mean(), geometry=geometry, scale=30)
+    .get('nd')
+)
+
+# Compute the UN-weighted mean of the NDWI image clipped to the region.
+unweighted = (
+    ndwi.clip(geometry)
+    .reduceRegion(
+        reducer=ee.Reducer.mean().unweighted(), geometry=geometry, scale=30
+    )
+    .get('nd')
+)
+
+# Observe the difference between weighted and unweighted reductions.
+display('weighted:', weighted)
+display('unweighted', unweighted)
+# [END earthengine__reducers11__unweighted]