.. _treadingraster:

Reading rasters
_______________

Reading files
+++++++++++++

.. code-block:: python

    from girs.rast.raster import Raster
    r = RasterReader('D:/tmp/chirps/chirps-v2.0.2016.01.10.tif')
    r = RasterReader(filename='D:/tmp/chirps/chirps-v2.0.2016.01.10.tif')
    print r.get_filename()

Outputs::

    D:/tmp/chirps/chirps-v2.0.2016.01.10.tif


Reading compressed files
++++++++++++++++++++++++

**ZIP files**

The zip-file ``chirps-v2.0.2016.01.10.tif.zip`` has only one member chirps-v2.0.2016.01.10.tif.

.. code-block:: python

    from girs.rast.raster import Raster
    r = RasterReader('D:/tmp/chirps/chirps-v2.0.2016.01.10.tif.zip')
    print r.get_filename()
    print r.get_rastername()
    print r.is_compressed()

Outputs::

    D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.01.10.tif.zip
    chirps-v2.0.2016.01.10.tif
    True


The zip-file ``chirps-v2.0.2016.Jan.10th.zip`` has also only one member chirps-v2.0.2016.01.10.tif. 
Filename and member name must not be the same.

.. code-block:: python

    from girs.rast.raster import Raster
    r = RasterReader('D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.Jan.10th.zip')
    print r.get_filename()
    print r.get_rastername()


Outputs::

    D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.Jan.10th.zip
    chirps-v2.0.2016.01.10.tif
    

The zip-file ``chirps-v2.0.2016.01.zip`` has two members: chirps-v2.0.2016.01.10.tif and chirps-v2.0.2016.01.10.tif.
The member name must be given in this case.
 
.. code-block:: python

    from girs.rast.raster import RasterReader
    r = RasterReader('D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.01.zip', 
                      member='chirps-v2.0.2016.01.10.tif')
    print r.get_filename()
    print r.get_rastername()
    r = RasterReader('D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.01.zip', 
                      member='chirps-v2.0.2016.01.11.tif')
    print r.get_filename()
    print r.get_rastername()


Outputs::

    D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.01.zip
    chirps-v2.0.2016.01.10.tif
    D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.01.zip
    chirps-v2.0.2016.01.11.tif

    
**GZIP files**

Gzip files have only one member, which has the same name as the compressed file. If the compressed file 
is renamed, the uncompressed file will have the new name without the suffix `.gz`

.. code-block:: python

    from girs.rast.raster import RasterReader
    r = RasterReader('D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.01.10.tif.gz')
    print r.get_filename()
    print r.get_rastername()
    

Outputs::

    D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.01.10.tif.gz
    D:/tmp/girs/chirps_basin/compressed/chirps-v2.0.2016.01.10.tif