Converting a Jupyter notebook to PySpark¶
To convert a Jupyter notebook to PySpark, you first need to make sure that you have Apache Spark installed on your computer. You can then use the findSpark package to automatically find and load Spark into your Jupyter notebook, like this:
Example
import findspark
findspark.init()
Once you have done this, you can use the pyspark package to create a SparkContext and SparkSession, which you can use to interact with Spark from your notebook.
Example
from pyspark import SparkContext
from pyspark.sql import SparkSession
sc = SparkContext()
spark = SparkSession(sc)
With these steps, you should be able to use PySpark in your Jupyter notebook just like you would in any other Python environment. Keep in mind that you may need to adjust your code to work with Spark's distributed computing model, as well as with the data structures and APIs provided by PySpark.
Performing spatial queries with PySpark¶
PySpark does not have built-in support for spatial data types or operations, so you cannot use it to directly manipulate geometry objects like you can with GeoPandas. However, you can still perform spatial queries on data stored in PySpark DataFrames by converting the data to a format that PySpark can work with, and then using the PySpark API to perform the necessary computations.
For example, you could use the ST_AsText and ST_GeomFromText functions from the PostGIS spatial extension for PostgreSQL to convert the geometry data to and from text strings, which PySpark can manipulate as regular string data. You could then use PySpark's built-in string manipulation functions, as well as user-defined functions (UDFs), to extract the spatial information you need from the geometry data.
Here is an example of how you might perform a spatial query on PySpark DataFrame data using this approach:
Example
# Define a UDF that converts a geometry object to a text string
from pyspark.sql.functions import udf
from pyspark.sql.types import StringType
def geom_to_text(geom):
return f"ST_AsText({geom})"
geom_to_text_udf = udf(geom_to_text, StringType())
# Define a UDF that converts a text string to a geometry object
def text_to_geom(text):
return f"ST_GeomFromText({text})"
text_to_geom_udf = udf(text_to_geom, StringType())
# Convert the geometry data to text strings
df = df.withColumn('geom_text', geom_to_text_udf('geom'))
# Use PySpark string functions to extract the X and Y coordinates from the text strings
df = df.withColumn('x', df['geom_text'].substr(6, df['geom_text'].index(' ')).cast('double'))
df = df.withColumn('y', df['geom_text'].substr