earthengine-api/python/ee/featurecollection.py
2013-01-24 14:53:17 -08:00

100 lines
3.1 KiB
Python

# Copyright 2012 Google Inc. All Rights Reserved.
"""Representation of an Earth Engine FeatureCollection."""
# Using old-style python function naming on purpose to match the
# javascript version's naming.
# pylint: disable-msg=C6003,C6409
import collections
import numbers
import collection
import ee_exception
import feature
import image
import serializer
class FeatureCollection(collection.Collection):
def __init__(self, args, opt_column=None): # pylint: disable-msg=W0231
"""A representation of a FeatureCollection.
Args:
args: constructor argument. One of:
A string - The name of a collection.
A number - The ID of a Fusion Table.
A feature.
An array of features.
A dict - a collections's JSON description.
opt_column: The name of the column containing the geometry. This is
only useful when args is a string or a number.
Raises:
EEException: if passed something other than the above.
"""
if isinstance(args, feature.Feature):
args = [args]
if isinstance(args, basestring):
args = {'type': 'FeatureCollection', 'id': args}
if opt_column:
args['geo_column'] = opt_column
elif isinstance(args, numbers.Number):
args = {'type': 'FeatureCollection', 'table_id': args}
if opt_column:
args['geo_column'] = opt_column
elif isinstance(args, FeatureCollection):
args = dict(args._description) # pylint: disable-msg=W0212
elif isinstance(args, dict):
# This is the default, but we need to check it before we get to iterable.
pass
elif isinstance(args, collections.Iterable):
new_args = {
'type': 'FeatureCollection',
'features': [feature.Feature(x) for x in args]
}
args = new_args
else:
raise ee_exception.EEException('Unrecognized constructor argument.')
self._description = args
def getMapId(self, vis_params=None):
"""Fetch and return a map id and token, suitable for use in a Map overlay.
Args:
vis_params: The visualization parameters. Currently only one parameter,
'color', containing a hex RGB color string is allowed.
Returns:
An object containing a mapid string, an access token, plus a DrawVector
image wrapping this collection.
"""
painted = image.Image({
'algorithm': 'DrawVector',
'collection': self,
'color': (vis_params or {}).get('color', '000000')
})
return painted.getMapId({})
def map(self,
algorithm,
opt_dynamicArgs=None,
opt_constantArgs=None,
opt_destination=None):
"""Maps an algorithm over a collection. See ee.Collection.mapInternal()."""
return self.mapInternal(feature.Feature, algorithm,
opt_dynamicArgs, opt_constantArgs, opt_destination)
def __str__(self):
"""Writes out the collection in a human-readable form."""
return 'FeatureCollection(%s)' % serializer.toJSON(self._description)
def __repr__(self):
"""Writes out the collection in an eval-able form."""
return 'ee.FeatureCollection(%s)' % self._description