GeoPySpark
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GeoPySpark is not currently under active development. We will try and address PRs and Issues, but it may take some time as most of our resources are devoted to other projects now. There is a chance that this project will be revisted in the future, so it is by no means dead.
GeoPySpark is a Python bindings library for GeoTrellis <http://geotrellis.io>
, a Scala
library for working with geospatial data in a distributed environment.
By using PySpark <http://spark.apache.org/docs/latest/api/python/pyspark.html>
, GeoPySpark is
able to provide an interface into the GeoTrellis framework.
Documentation <https://geopyspark.readthedocs.io>
_Gitter <https://gitter.im/geotrellis/geotrellis>
_Here is a quick example of GeoPySpark. In the following code, we take NLCD data of the state of Pennsylvania from 2011, and do a masking operation on it with a Polygon that represents an area of interest. This masked layer is then saved.
If you wish to follow along with this example, you will need to download the NLCD data and unzip it.. Running these two commands will complete these tasks for you:
.. code:: console
curl -o /tmp/NLCD2011_LC_Pennsylvania.zip "https://s3-us-west-2.amazonaws.com/prd-tnm/StagedProducts/NLCD/data/2011/landcover/states/NLCD2011_LC_Pennsylvania.zip?ORIG=513_SBDDG" unzip -d /tmp /tmp/NLCD2011_LC_Pennsylvania.zip
.. code:: python
import geopyspark as gps
from pyspark import SparkContext from shapely.geometry import box
conf = gps.geopyspark_conf(appName="geopyspark-example", master="local[*]") sc = SparkContext(conf=conf)
raster_layer = gps.geotiff.get(layer_type=gps.LayerType.SPATIAL, uri='/tmp/NLCD2011_LC_Pennsylvania.tif', num_partitions=100)
tiled_layer = raster_layer.tile_to_layout(layout=gps.GlobalLayout(), target_crs=3857)
area_of_interest = box(-75.229225, 40.003686, -75.107345, 40.084375)
masked = tiled_layer.mask(geometries=area_of_interest)
pyramided_mask = masked.pyramid()
for pyramid in pyramided_mask.levels.values(): gps.write(uri='file:///tmp/pa-nlcd-2011', layer_name='north-west-philly', tiled_raster_layer=pyramid)
For additional examples, check out the Jupyter notebook demos <./notebook-demos>
_.
============ ============ Requirement Version ============ ============ Java >=1.8 Scala >=2.11 Python 3.3 - 3.6 Spark >=2.1.1 ============ ============
Java 8 and Scala 2.11 are needed for GeoPySpark to work, as they are required by
GeoTrellis. In addition, Spark needs to be installed and configured with the
environment variable SPARK_HOME
set.
You can test to see if Spark is installed properly by running the following in the terminal:
.. code:: console
echo $SPARK_HOME /usr/local/bin/spark
If the return is a path leading to your Spark folder, then it means that Spark
has been configured correctly. If SPARK_HOME
is unset or empty, you'll need to add it
to your PATH
after noting where Spark is installed on your system. For example,
a MacOS installation of Spark 2.3.0 via HomeBrew would set SPARK_HOME
as follows:
.. code:: bash
export SPARK_HOME=/usr/local/Cellar/apache-spark/2.3.0/libexec/
Before installing, check the above Requirements
_ table to make sure that the
requirements are met.
Installing From Pip
To install via ``pip`` open the terminal and run the following:
.. code:: console
pip install geopyspark
geopyspark install-jar
The first command installs the python code and the `geopyspark` command
from PyPi. The second downloads the backend jar file, which is too large
to be included in the pip package, and installs it to the GeoPySpark
installation directory. For more information about the ``geopyspark``
command, see the `GeoPySpark CLI`_ section.
Installing From Source
If you would rather install from source, clone the GeoPySpark repo and enter it.
.. code:: console
git clone https://github.com/locationtech-labs/geopyspark.git cd geopyspark make install
This will assemble the backend-end jar
that contains the Scala code,
move it to the jars
sub-package, and then runs the setup.py
script.
Note:
If you have altered the global behavior of sbt
this install may
not work the way it was intended.
Uninstalling
To uninstall GeoPySpark, run the following in the terminal:
.. code:: console
pip uninstall geopyspark
rm .local/bin/geopyspark
Contact and Support
-------------------
If you need help, have questions, or like to talk to the developers (let us
know what you're working on!) you can contact us at:
* `Gitter <https://gitter.im/geotrellis/geotrellis>`_
* `Mailing list <https://locationtech.org/mailman/listinfo/geotrellis-user>`_
As you may have noticed from the above links, those are links to the GeoTrellis
gitter channel and mailing list. This is because this project is currently an
offshoot of GeoTrellis, and we will be using their mailing list and gitter
channel as a means of contact. However, we will form our own if there is a need
for it.
GeoPySpark CLI
--------------
When GeoPySpark is installed, it comes with a script which can be accessed
from anywhere on you computer. This script is used to facilitate management
of the GeoPySpark jar file that must be installed in order for GeoPySpark to
work correctly. Here are the available commands:
.. code:: console
geopyspark -h, --help // return help string and exit
geopyspark install-jar // downloads jar file to default location, which is geopyspark install dir
geopyspark install-jar -p, --path [download/path] //downloads the jar file to location specified
geopyspark jar-path //returns the relative path of the jar file
geopyspark jar-path -a, --absolute //returns the absolute path of the jar file
``geopyspark install-jar`` is only needed when installing GeoPySpark through
``pip``; and it **must** be ran before using GeoPySpark. If no path is selected,
then the jar will be installed wherever GeoPySpark was installed.
The second and third commands are for getting the location of the jar file.
These can be used regardless of installation method. However, if installed
through ``pip``, then the jar must be downloaded first or these commands
will not work.
Developing GeoPySpark
---------------------
Contributing
Feedback and contributions to GeoPySpark are always welcomed.
A CLA is required for contribution, see Contributing <docs/contributing.rst>
_ for more
information.
Installing for Developers
.. code:: console
make build
pip install -e .
``make build`` will assemble the back-end ``jar`` and move it the ``jars``
sub-package. The second command will install GeoPySpark in "editable" mode.
Meaning any changes to the source files will also appear in your system
installation.
Within a virtualenv
===================
It's possible that you may run into issues when performing the ``pip install -e .``
described above with a Python virtualenv active. If you're having trouble with
Python finding installed libraries within the virtualenv, try adding the virtualenv
site-packages directory to your PYTHONPATH:
.. code:: console
workon <your-geopyspark-virtualenv-name>
export PYTHONPATH=$VIRTUAL_ENV/lib/<your python version>/site-packages
Replace ``<your python version`` with whatever Python version
``virtualenvwrapper`` is set to. Once you've set PYTHONPATH, re-install
GeoPySpark using the instructions in "Installing for Developers" above.
Running GeoPySpark Tests
GeoPySpark uses the pytest <https://docs.pytest.org/en/latest/>
_ testing
framework to run its unittests. If you wish to run GeoPySpark's unittests,
then you must first clone this repository to your machine. Once complete,
go to the root of the library and run the following command:
.. code:: console
pytest
This will then run all of the tests present in the GeoPySpark library.
Note: The unittests require additional dependencies in order to pass fully.
pyproj <https://pypi.python.org/pypi/pyproj?>
, colortools <https://pypi.python.org/pypi/colortools/0.1.2>
,
and matplotlib <https://pypi.python.org/pypi/matplotlib/2.0.2>
_ (only for >=Python3.4) are needed to
ensure that all of the tests pass.
Developing GeoPySpark With GeoNotebook
**Note**: Before begining this section, it should be noted that python-mapnik,
a dependency for GeoNotebook, has been found to be difficult to install. If
problems are encountered during installation, a possible work around would be
to run ``make wheel`` and then do ``docker cp`` the ``wheel`` into the
GeoPySpark docker container and install it from there.
`GeoNotebook <https://github.com/OpenGeoscience/geonotebook>`_ is a Jupyter
notebook extension that specializes in working with geospatial data. GeoPySpark
can be used with this notebook; which allows for a more interactive experience
when using the library. For this section, we will be installing both tools in a
virtual environment. It is recommended that you start with a new environment
before following this guide.
Because there's already documentation on how to install GeoPySpark in a virtual
environment, we won't go over it here. As for GeoNotebook, it also has a section
on `installation <https://github.com/OpenGeoscience/geonotebook#make-a-virtualenv-install-jupyternotebook-install-geonotebook>`_
so that will not be covered here either.
Once you've setup both GeoPySpark and GeoNotebook, all that needs to be done
is go to where you want to save/have saved your notebooks and execute this
command:
.. code:: console
jupyter notebook
This will open up the jupyter hub and will allow you to work on your notebooks.
It is also possible to develop with both GeoPySpark and GeoNotebook in editable mode.
To do so you will need to re-install and re-register GeoNotebook with Jupyter.
.. code:: console
pip uninstall geonotebook
git clone --branch feature/geotrellis https://github.com/geotrellis/geonotebook ~/geonotebook
pip install -r ~/geonotebook/prerequirements.txt
pip install -r ~/geonotebook/requirements.txt
pip install -e ~/geonotebook
jupyter serverextension enable --py geonotebook
jupyter nbextension enable --py geonotebook
make notebook
The default ``Geonotebook (Python 3)`` kernel will require the following environment variables to be defined:
.. code:: console
export PYSPARK_PYTHON="/usr/local/bin/python3"
export SPARK_HOME="/usr/local/apache-spark/2.1.1/libexec"
export PYTHONPATH="${SPARK_HOME}/python/lib/py4j-0.10.4-src.zip:${SPARK_HOME}/python/lib/pyspark.zip"
Make sure to define them to values that are correct for your system.
The ``make notebook`` command also makes used of ``PYSPARK_SUBMIT_ARGS`` variable defined in the ``Makefile``.
GeoNotebook/GeoTrellis integration in currently in active development and not part of GeoNotebook master.
The latest development is on a ``feature/geotrellis`` branch at ``<https://github.com/geotrellis/geonotebook>``.
Side Note For Developers
========================
An optional (but recommended!) step for developers is to place these
two lines of code at the top of your notebooks.
.. code:: console
%load_ext autoreload
%autoreload 2
This will make it so that you don't have to leave the notebook for your changes
to take affect. Rather, you just have to reimport the module and it will be
updated. However, there are a few caveats when using ``autoreload`` that can be
read `here <http://ipython.readthedocs.io/en/stable/config/extensions/autoreload.html#caveats>`_.
Using ``pip install -e`` in conjunction with ``autoreload`` should cover any
changes made, though, and will make the development experience much less
painful.