I would like to learn OSWlib or an equivalent library with idea that I can download GIS datasets as part of my kedro data processing pipelines.
I started following this example on the PyPI readme:
>>> from owslib.wms import WebMapService
>>> wms = WebMapService('http://wms.jpl.nasa.gov/wms.cgi', version='1.1.1')
>>> wms.identification.type
'OGC:WMS'
>>> wms.identification.version
'1.1.1'
>>> wms.identification.title
'JPL Global Imagery Service'
>>> wms.identification.abstract
'WMS Server maintained by JPL, worldwide satellite imagery.'
Available layers::
>>> list(wms.contents)
['us_landsat_wgs84', 'modis', 'global_mosaic_base', 'huemapped_srtm',
'srtm_mag', 'daily_terra', 'us_ned', 'us_elevation', 'global_mosaic',
'daily_terra_ndvi', 'daily_aqua_ndvi', 'daily_aqua_721', 'daily_planet',
'BMNG', 'srtmplus', 'us_colordem', None, 'daily_aqua', 'worldwind_dem',
'daily_terra_721']
Details of a layer::
>>> wms['global_mosaic'].title
'WMS Global Mosaic, pan sharpened'
>>> wms['global_mosaic'].boundingBoxWGS84
(-180.0, -60.0, 180.0, 84.0)
>>> wms['global_mosaic'].crsOptions
['EPSG:4326', 'AUTO:42003']
>>> wms['global_mosaic'].styles
{'pseudo_bright': {'title': 'Pseudo-color image (Uses IR and Visual bands,
542 mapping), gamma 1.5'}, 'pseudo': {'title': '(default) Pseudo-color
image, pan sharpened (Uses IR and Visual bands, 542 mapping), gamma 1.5'},
'visual': {'title': 'Real-color image, pan sharpened (Uses the visual
bands, 321 mapping), gamma 1.5'}, 'pseudo_low': {'title': 'Pseudo-color
image, pan sharpened (Uses IR and Visual bands, 542 mapping)'},
'visual_low': {'title': 'Real-color image, pan sharpened (Uses the visual
bands, 321 mapping)'}, 'visual_bright': {'title': 'Real-color image (Uses
the visual bands, 321 mapping), gamma 1.5'}}
Available methods, their URLs, and available formats::
>>> [op.name for op in wms.operations]
['GetTileService', 'GetCapabilities', 'GetMap']
>>> wms.getOperationByName('GetMap').methods
{'Get': {'url': 'http://wms.jpl.nasa.gov/wms.cgi?'}}
>>> wms.getOperationByName('GetMap').formatOptions
['image/jpeg', 'image/png', 'image/geotiff', 'image/tiff']
That's everything needed to make a request for imagery::
>>> img = wms.getmap( layers=['global_mosaic'],
... styles=['visual_bright'],
... srs='EPSG:4326',
... bbox=(-112, 36, -106, 41),
... size=(300, 250),
... format='image/jpeg',
... transparent=True
... )
>>> out = open('jpl_mosaic_visb.jpg', 'wb')
>>> out.write(img.read())
>>> out.close()
But I almost immediately ran into an error.
(vewnv) [galen@orcus Downloads]$ python
Python 3.11.3 (main, Jun 5 2023, 09:32:32) [GCC 13.1.1 20230429] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from owslib.wms import WebMapService
>>> wms = WebMapService('http://wms.jpl.nasa.gov/wms.cgi', version='1.1.1')
Traceback (most recent call last):
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/connection.py", line 203, in _new_conn
sock = connection.create_connection(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/util/connection.py", line 60, in create_connection
for res in socket.getaddrinfo(host, port, family, socket.SOCK_STREAM):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.11/socket.py", line 962, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
socket.gaierror: [Errno -2] Name or service not known
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/connectionpool.py", line 790, in urlopen
response = self._make_request(
^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/connectionpool.py", line 496, in _make_request
conn.request(
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/connection.py", line 395, in request
self.endheaders()
File "/usr/lib/python3.11/http/client.py", line 1278, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/usr/lib/python3.11/http/client.py", line 1038, in _send_output
self.send(msg)
File "/usr/lib/python3.11/http/client.py", line 976, in send
self.connect()
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/connection.py", line 243, in connect
self.sock = self._new_conn()
^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/connection.py", line 210, in _new_conn
raise NameResolutionError(self.host, self, e) from e
urllib3.exceptions.NameResolutionError: <urllib3.connection.HTTPConnection object at 0x7f77cd407310>: Failed to resolve 'wms.jpl.nasa.gov' ([Errno -2] Name or service not known)
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/requests/adapters.py", line 486, in send
resp = conn.urlopen(
^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/connectionpool.py", line 844, in urlopen
retries = retries.increment(
^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/urllib3/util/retry.py", line 515, in increment
raise MaxRetryError(_pool, url, reason) from reason # type: ignore[arg-type]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
urllib3.exceptions.MaxRetryError: HTTPConnectionPool(host='wms.jpl.nasa.gov', port=80): Max retries exceeded with url: /wms.cgi?service=WMS&request=GetCapabilities&version=1.1.1 (Caused by NameResolutionError("<urllib3.connection.HTTPConnection object at 0x7f77cd407310>: Failed to resolve 'wms.jpl.nasa.gov' ([Errno -2] Name or service not known)"))
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/owslib/wms.py", line 50, in WebMapService
return wms111.WebMapService_1_1_1(
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/owslib/map/wms111.py", line 75, in __init__
self._capabilities = reader.read(self.url, timeout=self.timeout)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/owslib/map/common.py", line 65, in read
u = openURL(spliturl[0], spliturl[1], method='Get',
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/owslib/util.py", line 209, in openURL
req = requests.request(method.upper(), url_base, headers=headers, **rkwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/requests/api.py", line 59, in request
return session.request(method=method, url=url, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/requests/sessions.py", line 589, in request
resp = self.send(prep, **send_kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/requests/sessions.py", line 703, in send
r = adapter.send(request, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/galen/Downloads/vewnv/lib/python3.11/site-packages/requests/adapters.py", line 519, in send
raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='wms.jpl.nasa.gov', port=80): Max retries exceeded with url: /wms.cgi?service=WMS&request=GetCapabilities&version=1.1.1 (Caused by NameResolutionError("<urllib3.connection.HTTPConnection object at 0x7f77cd407310>: Failed to resolve 'wms.jpl.nasa.gov' ([Errno -2] Name or service not known)"))
The server used in the example (http://wms.jpl.nasa.gov) was beginning to be phased out over 10 years ago (and seemingly finally decommissioned toward the end of 2014) and is no longer accessible.
The message on the site prior to its decommissioning indicated that it would be "replaced by the Global Imagery Browse Services (GIBS) provided by the Earth Science Data and Information System (ESDIS) Project: http://earthdata.nasa.gov/gibs".
A cursory clickthrough of the linked replacement site shows that NASA still provides a WMS service, albeit through different Service Endpoints listed on the Access Basics documentation page. Replacing the dead link in your code with a listed service endpoint best suiting your needs should get you back on the right track.
Interestingly, the example cited in the README you seem to be basing this code off of first appeared at least 17 years ago, so it’s quite old and not surprising that it’s broken. I might consider filing an Issue to have it updated to something more relevant.