Pure Python implementation of the Spark RDD interface.
.. image:: https://raw.githubusercontent.com/svenkreiss/pysparkling/master/logo/logo-w100.png :target: https://github.com/svenkreiss/pysparkling
Pysparkling provides a faster, more responsive way to develop programs for PySpark. It enables code intended for Spark applications to execute entirely in Python, without incurring the overhead of initializing and passing data through the JVM and Hadoop. The focus is on having a lightweight and fast implementation for small datasets at the expense of some data resilience features and some parallel processing features.
How does it work? To switch execution of a script from PySpark to pysparkling, have the code initialize a pysparkling Context instead of a SparkContext, and use the pysparkling Context to set up your RDDs. The beauty is you don't have to change a single line of code after the Context initialization, because pysparkling's API is (almost) exactly the same as PySpark's. Since it's so easy to switch between PySpark and pysparkling, you can choose the right tool for your use case.
When would I use it? Say you are writing a Spark application because you need robust computation on huge datasets, but you also want the same application to provide fast answers on a small dataset. You're finding Spark is not responsive enough for your needs, but you don't want to rewrite an entire separate application for the small-answers-fast problem. You'd rather reuse your Spark code but somehow get it to run fast. Pysparkling bypasses the stuff that causes Spark's long startup times and less responsive feel.
Here are a few areas where pysparkling excels:
.. code-block:: bash
pip install pysparkling[s3,hdfs,http,streaming]
Documentation <http://pysparkling.trivial.io>
_:
.. image:: https://raw.githubusercontent.com/svenkreiss/pysparkling/master/docs/readthedocs.png :target: http://pysparkling.trivial.io
Other links:
Github <https://github.com/svenkreiss/pysparkling>
,
Issue Tracker <https://github.com/svenkreiss/pysparkling/issues>
,
|pypi-badge|
.. |pypi-badge| image:: https://badge.fury.io/py/pysparkling.svg :target: https://pypi.python.org/pypi/pysparkling/
s3://
, hdfs://
, gs://
, http://
and file://
for Amazon S3, HDFS, Google Storage, web and local file access.
Specify multiple files separated by comma.
Resolves *
and ?
wildcards..gz
, .zip
, .lzma
, .xz
, .bz2
, .tar
,
.tar.gz
and .tar.bz2
compressed files.
Supports reading of .7z
files.multiprocessing.Pool
,
concurrent.futures.ThreadPoolExecutor
or any other Pool-like
objects that have a map(func, iterable)
method.pip install pysparkling
).
Some file access methods have optional dependencies:
boto
for AWS S3, requests
for http, hdfs
for hdfsSome demos are in the notebooks
docs/demo.ipynb <https://github.com/svenkreiss/pysparkling/blob/master/docs/demo.ipynb>
_
and
docs/iris.ipynb <https://github.com/svenkreiss/pysparkling/blob/master/docs/iris.ipynb>
_
.
Word Count
.. code-block:: python
from pysparkling import Context
counts = (
Context()
.textFile('README.rst')
.map(lambda line: ''.join(ch if ch.isalnum() else ' ' for ch in line))
.flatMap(lambda line: line.split(' '))
.map(lambda word: (word, 1))
.reduceByKey(lambda a, b: a + b)
)
print(counts.collect())
which prints a long list of pairs of words and their counts.