Export multiple Images from collection to Google Drive not working with Google Earth Engine Python API 0.1.238

Question

I am struggling with Google Earth Engine Python API version 0.1.238 to export images from the Landsat EVI collection (from 2002 to 2020, but i started with a small sample) to my Google Drive, which are essential to my research.

At first i wanted to add these images directly in QGis, but apparently the version of the Earth Engine plugin of QGis is outdated for such task (i.e. export + impossible to loop the Map.addLayer command).

So I finally built a python script prompting no errors, but my Google Drive folder is still empty. Here is what gives the task.status() command after the task:

{'state': 'READY', 'description': 'myExportImageTask', 'creation_timestamp_ms': 1602830108152, 'update_timestamp_ms': 1602830108152, 'start_timestamp_ms': 0, 'task_type': 'EXPORT_IMAGE', 'id': '2QGWJCVBPUOOCTNFIIDYLKRQ', 'name': 'projects/earthengine-legacy/operations/2QGWJCVBPUOOCTNFIIDYLKRQ'}

How could i make this script work ?

import ee
ee.Initialize()

# USDA NAIP ImageCollection
collection = ee.ImageCollection('LANDSAT/LE07/C01/T1_32DAY_EVI')

# create a roi
polys = ee.Geometry.Polygon(
        [[[37.5, 25.5],
          [40.5, 25.5],
          [40.5, 28.5],
          [37.5, 28.5]]])

# filter the ImageCollection using the roi
naip = collection.filterBounds(polys)

# filter dates
naip_dates = naip.filterDate('2002-04-01', '2002-08-07')
mosaic = naip_dates.mosaic()

# print out the number of images in the ImageCollection
count = naip_dates.size().getInfo()
print("Count: ", count)

# export the ImageCollection to Google Drive
img_lst = naip_dates.toList(100)

for i in range(0, count):
    image = ee.Image(img_lst.get(i))
    name = image.get('system:index').getInfo()
    task = ee.batch.Export.image.toDrive(image=image,
                                         region=polys,
                                         folder='32DAY_EVI',
                                         scale=30,
                                         crs='EPSG:3857')
    task.start()
    print(task.status())

I also tested such simple script to test my Google Drive and still nothing in my folder (not even the creation of the folder itself):

import ee
ee.Initialize()

landsat = ee.Image('LANDSAT/LC08/C01/T1_TOA/LC08_123032_20140515').select(['B4', 'B3', 'B2'])

geometry = ee.Geometry.Rectangle([116.2621, 39.8412, 116.4849, 40.01236])

task_config = {
    'scale': 30,  
    'region': geometry,
    'folder':'GEEtest'
}

task = ee.batch.Export.image.toDrive(landsat, 'TEST_todrive', **task_config)
task.start()

I am wondering if it is not an issue with my Credentials. I did the earthengine authenticate step without any issue, but is there something else to do to link GEE to GDrive ?

Answer 1

Monday morning, I check my Google Drive, and it is full of data! So my scripts are working (especially the 1st one which is very efficient to extract a collection of images).

My guess is that the servers were down, or overloaded for few days, because now I have a print of task.status() for every image exported (every 10-20s) while before it was only one print for almost an hour.

Sorry for bothering, but at least this script should be useful to some people.

Answer 2

You can use a while loop as the task is active and print a statement every n seconds.

for i in range(0, count):
    image = ee.Image(collection.get(i))
    name = image.get('system:index').getInfo()
    task = ee.batch.Export.image.toDrive(image=image,
                                     region=polys,
                                     folder='32DAY_EVI',
                                     scale=30,
                                     crs='EPSG:3857')
    
    task.start()
    
    while task.active():
        print('Waiting on (id: {}).'.format(task.id))
        time.sleep(15)

Don't forget to import time.