ee.ImageCollection.toDictionary

  • The ImageCollection.toDictionary() method extracts properties from a feature as a dictionary.

  • By default, toDictionary() extracts all non-system properties, but you can specify a list of properties to extract.

  • The examples demonstrate how to use toDictionary() in both JavaScript and Python to retrieve collection properties.

 Extract properties from a feature as a dictionary.

UsageReturns
ImageCollection.toDictionary(properties)Dictionary
ArgumentTypeDetails
this: elementElementThe feature to extract the property from.
propertiesList, default: nullThe list of properties to extract. Defaults to all non-system properties.

Examples

Code Editor (JavaScript)

// A contrived, empty image collection for simple demonstration.
var col = ee.ImageCollection([]);
print('Collection without properties', col);

// Set collection properties using a dictionary.
col = col.set({
  project_name: 'biomass_tracking',
  project_id: 3,
  plot_ids: ee.Array([7, 11, 20])
});

// Set collection properties using a series of key-value pairs.
col = col.set('project_year', 2018,
              'rgb_vis', 'false_color');

print('Collection with properties', col);

// Get a dictionary of collection property keys and values.
print('Property keys and values (ee.Dictionary)', col.toDictionary());

// Get the value of a collection property. To use the result of
// ee.ImageCollection.get in further computation, you need to cast it to the
// appropriate class, for example, ee.Number(result) or ee.String(result).
print('Project ID (ambiguous object)', col.get('project_id'));

// Get the value of a string collection property as an ee.String object.
print('Project name (ee.String)', col.getString('project_name'));

// Get the value of a numeric collection property as an ee.Number object.
print('Project year (ee.Number)', col.getNumber('project_year'));

// Get the value of an ee.Array collection property as an ee.Array object.
print('Plot IDs (ee.Array)', col.getArray('plot_ids'));

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 contrived, empty image collection for simple demonstration.
col = ee.ImageCollection([])
print('Collection without properties:', col.getInfo())

# Set collection properties using a dictionary.
col = col.set({
    'project_name': 'biomass_tracking',
    'project_id': 3,
    'plot_ids': ee.Array([7, 11, 20])
})

# Set collection properties using a series of key-value pairs.
col = col.set('project_year', 2018,
              'rgb_vis', 'false_color')

print('Collection with properties:', col.getInfo())

# Get a dictionary of collection property keys and values.
print('Property keys and values (ee.Dictionary):', col.toDictionary().getInfo())

# Get the value of a collection property. To use the result of
# ee.ImageCollection.get in further computation, you need to cast it to the
# appropriate class, for example, ee.Number(result) or ee.String(result).
print('Project ID (ambiguous object):', col.get('project_id').getInfo())

# Get the value of a string collection property as an ee.String object.
print('Project name (ee.String):', col.getString('project_name').getInfo())

# Get the value of a numeric collection property as an ee.Number object.
print('Project year (ee.Number):', col.getNumber('project_year').getInfo())

# Get the value of an ee.Array collection property as an ee.Array object.
print('Plot IDs (ee.Array):', col.getArray('plot_ids').getInfo())