ee.Dictionary.select

  • The select method on a dictionary returns a new dictionary containing only the specified keys.

  • Keys can be selected using a list of exact key names or regular expressions.

  • The ignoreMissing argument, which defaults to false, can be set to true to prevent errors if a selector doesn't match any keys.

 Returns a dictionary with only the specified keys.

UsageReturns
Dictionary.select(selectors, ignoreMissing)Dictionary
ArgumentTypeDetails
this: dictionaryDictionary
selectorsListA list of keys or regular expressions to select.
ignoreMissingBoolean, default: falseIgnore 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}));

Python setup

See the Python Environment page for information on the Python API and using geemap for interactive development.

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())