# Landsat Util
# License: CC0 1.0 Universal
import json
import time
import requests
import settings
from utils import three_digit, create_paired_list
[docs]class Search(object):
""" The search class """
def __init__(self):
self.api_url = settings.API_URL
[docs] def search(self, paths_rows=None, lat=None, lon=None, start_date=None, end_date=None, cloud_min=None,
cloud_max=None, limit=1):
"""
The main method of Search class. It searches Development Seed's Landsat API.
:param paths_rows:
A string in this format: "003,003,004,004". Must be in pairs and separated by comma.
:type paths_rows:
String
:param lat:
The latitude
:type lat:
String, float, integer
:param lon:
The The longitude
:type lon:
String, float, integer
:param start_date:
Date string. format: YYYY-MM-DD
:type start_date:
String
:param end_date:
date string. format: YYYY-MM-DD
:type end_date:
String
:param cloud_min:
float specifying the minimum percentage. e.g. 4.3
:type cloud_min:
float
:param cloud_max:
float specifying the maximum percentage. e.g. 78.9
:type cloud_max:
float
:param limit:
integer specigying the maximum results return.
:type limit:
integer
:returns:
dict
:example:
>>> search = Search()
>>> search('003,003', '2014-01-01', '2014-06-01')
>>> {
'status': u'SUCCESS',
'total_returned': 1,
'total': 1,
'limit': 1
'results': [
{
'sat_type': u'L8',
'sceneID': u'LC80030032014142LGN00',
'date': u'2014-05-22',
'path': u'003',
'thumbnail': u'http://....../landsat_8/2014/003/003/LC80030032014142LGN00.jpg',
'cloud': 33.36,
'row': u'003
}
]
}
"""
search_string = self.query_builder(paths_rows, lat, lon, start_date, end_date, cloud_min, cloud_max)
# Have to manually build the URI to bypass requests URI encoding
# The api server doesn't accept encoded URIs
r = requests.get('%s?search=%s&limit=%s' % (self.api_url, search_string, limit))
r_dict = json.loads(r.text)
result = {}
if 'error' in r_dict:
result['status'] = u'error'
result['code'] = r_dict['error']['code']
result['message'] = r_dict['error']['message']
elif 'meta' in r_dict:
result['status'] = u'SUCCESS'
result['total'] = r_dict['meta']['results']['total']
result['limit'] = r_dict['meta']['results']['limit']
result['total_returned'] = len(r_dict['results'])
result['results'] = [{'sceneID': i['sceneID'],
'sat_type': u'L8',
'path': three_digit(i['path']),
'row': three_digit(i['row']),
'thumbnail': i['browseURL'],
'date': i['acquisitionDate'],
'cloud': i['cloudCoverFull']}
for i in r_dict['results']]
return result
[docs] def query_builder(self, paths_rows=None, lat=None, lon=None, start_date=None, end_date=None,
cloud_min=None, cloud_max=None):
""" Builds the proper search syntax (query) for Landsat API.
:param paths_rows:
A string in this format: "003,003,004,004". Must be in pairs and separated by comma.
:type paths_rows:
String
:param lat:
The latitude
:type lat:
String, float, integer
:param lon:
The The longitude
:type lon:
String, float, integer
:param start_date:
Date string. format: YYYY-MM-DD
:type start_date:
String
:param end_date:
date string. format: YYYY-MM-DD
:type end_date:
String
:param cloud_min:
float specifying the minimum percentage. e.g. 4.3
:type cloud_min:
float
:param cloud_max:
float specifying the maximum percentage. e.g. 78.9
:type cloud_max:
float
:returns:
String
"""
query = []
or_string = ''
and_string = ''
search_string = ''
if paths_rows:
# Coverting rows and paths to paired list
new_array = create_paired_list(paths_rows)
paths_rows = ['(%s)' % self.row_path_builder(i[0], i[1]) for i in new_array]
or_string = '+OR+'.join(map(str, paths_rows))
if start_date and end_date:
query.append(self.date_range_builder(start_date, end_date))
elif start_date:
query.append(self.date_range_builder(start_date, '2100-01-01'))
elif end_date:
query.append(self.date_range_builder('2009-01-01', end_date))
if cloud_min and cloud_max:
query.append(self.cloud_cover_prct_range_builder(cloud_min, cloud_max))
elif cloud_min:
query.append(self.cloud_cover_prct_range_builder(cloud_min, '100'))
elif cloud_max:
query.append(self.cloud_cover_prct_range_builder('-1', cloud_max))
if lat and lon:
query.append(self.lat_lon_builder(lat, lon))
if query:
and_string = '+AND+'.join(map(str, query))
if and_string and or_string:
search_string = and_string + '+AND+(' + or_string + ')'
else:
search_string = or_string + and_string
return search_string
[docs] def row_path_builder(self, path='', row=''):
"""
Builds row and path query.
:param path:
Landsat path. Must be three digits
:type path:
String
:param row:
Landsat row. Must be three digits
:type row:
String
:returns:
String
"""
return 'path:%s+AND+row:%s' % (path, row)
[docs] def date_range_builder(self, start='2013-02-11', end=None):
"""
Builds date range query.
:param start:
Date string. format: YYYY-MM-DD
:type start:
String
:param end:
date string. format: YYYY-MM-DD
:type end:
String
:returns:
String
"""
if not end:
end = time.strftime('%Y-%m-%d')
return 'acquisitionDate:[%s+TO+%s]' % (start, end)
[docs] def cloud_cover_prct_range_builder(self, min=0, max=100):
"""
Builds cloud cover percentage range query.
:param min:
float specifying the minimum percentage. Default is 0
:type min:
float
:param max:
float specifying the maximum percentage. Default is 100
:type max:
float
:returns:
String
"""
return 'cloudCoverFull:[%s+TO+%s]' % (min, max)
[docs] def lat_lon_builder(self, lat=0, lon=0):
""" Builds lat and lon query.
:param lat:
The latitude. Default is 0
:type lat:
float
:param lon:
The The longitude. Default is 0
:type lon:
float
:returns:
String
"""
return ('upperLeftCornerLatitude:[%s+TO+1000]+AND+lowerRightCornerLatitude:[-1000+TO+%s]'
'+AND+lowerLeftCornerLongitude:[-1000+TO+%s]+AND+upperRightCornerLongitude:[%s+TO+1000]'
% (lat, lat, lon, lon))