Page Summary
-
The
selectmethod 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
ignoreMissingargument, which defaults to false, can be set to true to prevent errors if a selector doesn't match any 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 }));
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 )
