pyows

pyows is a library to help building an OWS compatible service or client. It helps building requests and parsing them and also provides object types to be serialized and sent as responses.

Installation

Use the package manager pip to install pyows.

pip install pyows

Usage

pyows can be used to both parse/encode OWS requests and to parse/encode objects for the various services.

Example: Parsing a WCS 2.0 GetCoverage request:

>>> from ows.wcs.v20.decoders import xml_decode_get_coverage
>>>
>>> request = b"""<?xml version="1.0" encoding="UTF-8"?>
... <wcs:GetCoverage
...     xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
...     xsi:schemaLocation="http://www.opengis.net/wcs/2.0 http://schemas.opengis.net/wcs/2.0/wcsAll.xsd"
...     xmlns="http://www.opengis.net/wcs/2.0"
...     xmlns:wcs="http://www.opengis.net/wcs/2.0"
...     service="WCS"
...     version="2.0.1">
...     <wcs:CoverageId>a</wcs:CoverageId>
... </wcs:GetCoverage>
... """
>>> print(xml_decode_get_coverage(request))
GetCoverageRequest(coverage_id='a', format=None, mediatype=None, subsetting_crs=None, output_crs=None, subsets=[], scalefactor=None, scales=[], interpolation=None, axis_interpolations=[], range_subset=None)

The other way around:

>>> from ows.wcs.v20 import GetCoverageRequest, Trim, Slice
>>> request = GetCoverageRequest(
...     coverage_id='a',
...     subsets=[
...         Trim(dimension='x', low=1.2, high=2.2),
...         Trim(dimension='y', low=3),
...         Slice(dimension='time', point='2018-05-07')
...     ]
... )
>>> print(xml_encode_get_coverage(request, pretty_print=True).value.decode('utf-8'))
<wcs:GetCoverage xmlns:crs="http://www.opengis.net/wcs/crs/1.0" xmlns:eop="http://www.opengis.net/eop/2.0" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:gmlcov="http://www.opengis.net/gmlcov/1.0" xmlns:int="http://www.opengis.net/wcs/interpolation/1.0" xmlns:ogc="http://www.opengis.net/ogc" xmlns:om="http://www.opengis.net/om/2.0" xmlns:ows="http://www.opengis.net/ows/2.0" xmlns:rsub="http://www.opengis.net/wcs/range-subsetting/1.0" xmlns:scal="http://www.opengis.net/wcs/scaling/1.0" xmlns:swe="http://www.opengis.net/swe/2.0" xmlns:wcs="http://www.opengis.net/wcs/2.0" xmlns:wcseo="http://www.opengis.net/wcs/wcseo/1.0" xmlns:xlink="http://www.w3.org/1999/xlink" service="WCS" version="2.0.1">
  <wcs:CoverageId>a</wcs:CoverageId>
  <wcs:DimensionTrim>
    <wcs:Dimension>x</wcs:Dimension>
    <wcs:TrimLow>1.2</wcs:TrimLow>
    <wcs:TrimHigh>2.2</wcs:TrimHigh>
  </wcs:DimensionTrim>
  <wcs:DimensionTrim>
    <wcs:Dimension>y</wcs:Dimension>
    <wcs:TrimLow>3</wcs:TrimLow>
  </wcs:DimensionTrim>
  <wcs:DimensionSlice>
    <wcs:Dimension>time</wcs:Dimension>
    <wcs:SlicePoint>2018-05-07</wcs:SlicePoint>
  </wcs:DimensionSlice>
</wcs:GetCoverage>

Currently supported OWS

• OWS common
  • 2.0:
    • Capabilities related encoding
• WCS
  • 2.0:
    • Request encoding/decoding for (both XML/KVP)
      • GetCapabilities
      • DescribeCoverage
      • GetCoverage
    • Response encoding
      • Capabilities
      • CoverageDescriptions
  • 2.1
    • Response encoding for
      • CoverageDescriptions

Roadmap

• Full support of WCS 2.x including EO-WCS application profile and all extensions
• Support for WPS 2.0 requests and responses
• Support for WMS request and responses for all versions

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT