AI-generated Key Takeaways
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Dictionary.select()
returns a new dictionary containing only the specified keys from the original dictionary. -
Keys can be selected by providing a list of key names or regular expressions.
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The
ignoreMissing
parameter, when set to true, prevents errors if a selector doesn't match any key in the dictionary.
Usage | Returns |
---|---|
Dictionary.select(selectors, ignoreMissing) | Dictionary |
Argument | Type | Details |
---|---|---|
this: dictionary | Dictionary | |
selectors | List | A list of keys or regular expressions to select. |
ignoreMissing | Boolean, default: false | Ignore selectors that don't match at least 1 key. |
Examples
Code Editor (JavaScript)
// A dictionary (e.g. results of ee.Image.reduceRegion of an S2 image). var dict = ee.Dictionary({ B1: 182, B2: 219, B3: 443 }); print('Select keys by name', dict.select(['B1', 'B2'])); print('Select keys by regex', dict.select(['B[1-2]'])); print('Set ignoreMissing as true to avoid an unmatched key error', dict.select({selectors: ['B1', 'B2', 'Region'], ignoreMissing: true}));
import ee import geemap.core as geemap
Colab (Python)
# A dictionary (e.g. results of ee.Image.reduceRegion of an S2 image). dic = ee.Dictionary({ 'B1': 182, 'B2': 219, 'B3': 443 }) print('Select keys by name:', dic.select(['B1', 'B2']).getInfo()) print('Select keys by regex:', dic.select(['B[1-2]']).getInfo()) dic_select = dic.select(**{'selectors': ['B1', 'B2', 'Region'], 'ignoreMissing': True}) print('Set ignoreMissing as true to avoid an unmatched key error:', dic_select.getInfo())