ee.Dictionary.select

AI-generated Key Takeaways

• 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.

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}));

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
})

display('Select keys by name:', dic.select(['B1', 'B2']))
display('Select keys by regex:', dic.select(['B[1-2]']))

dic_select = dic.select(**{'selectors': ['B1', 'B2', 'Region'],
                           'ignoreMissing': True})
display('Set ignoreMissing as true to avoid an unmatched key error:',
        dic_select)