Three APIs of Spark¶
RDD (2011, spark 1.0)
DataFrames (2013, spark 1.3)
Datasets (2015, spark 1.6)
Spark SQL, DataFrames and Datasets¶
Spark SQL is a Spark module for structured data processing.
Unlike RDD, Spark SQL provides Spark with more information about the structure of both the data and the computation being performed.
There are several ways to interact with Spark SQL including SQL and the Dataset API.
Spark SQL¶
One use of Spark SQL is to execute SQL queries.
Spark SQL can also be used to read data from an existing Hive installation.
When running SQL from within another programming language the results will be returned as a Dataset/DataFrame.
Spark Datasets¶
A Dataset is a distributed collection of data.
Dataset can be constructed from JVM objects and then manipulated using functional transformations (
map, flatMap, filter
, etc.).The Dataset API is available in Scala and Java.
Python does not have the support for the Dataset API. But due to Python’s dynamic nature, many of the benefits of the Dataset API are already available (i.e. you can access the field of a row by name naturally row.columnName).
Spark DataFrames¶
A DataFrame is a Dataset organized into named columns.
It is conceptually equivalent to a table in a relational database or a data frame in R/Python, but with richer optimizations under the hood.
DataFrames can be constructed from a wide array of sources such as:
- structured data files,
- tables in Hive,
- external databases, or
- existing RDDs.
The DataFrame API is available in Scala, Java, Python, and R.
Spark session and spark context¶
What is SparkContext¶
Spark SparkContext is an entry point to Spark and defined in org.apache.spark package since 1.x and used to programmatically create Spark RDD, accumulators and broadcast variables on the cluster. Since Spark 2.0 most of the functionalities (methods) available in SparkContext are also available in SparkSession. Its object sc is default available in spark-shell and it can be programmatically created using SparkContext class.
What is SparkSession¶
SparkSession introduced in version 2.0 and and is an entry point to underlying Spark functionality in order to programmatically create Spark RDD, DataFrame and DataSet. It’s object spark is default available in spark-shell and it can be created programmatically using SparkSession builder pattern.
Start a Spark session¶
import findspark
findspark.init('/opt/apps/SPARK3/spark-current')
from pyspark.sql import SparkSession
spark = SparkSession.builder.appName("Python Spark").config('spark.port.maxRetries',50).getOrCreate()
spark.sparkContext.getConf().getAll()
spark.sparkContext.uiWebUrl
Setting default log level to "WARN". To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel). 23/11/22 11:51:27 WARN [Thread-6] Client: Neither spark.yarn.jars nor spark.yarn.archive is set, falling back to uploading libraries under SPARK_HOME.
'http://master-1-1.c-a637e78383e5fe3e.cn-zhangjiakou.emr.aliyuncs.com:4040'
Creating DataFrames¶
Convert an RDD to a DataFrame¶
sc = spark.sparkContext # When you create a SparkSession object, SparkContext is also created and can be retrieved using spark.sparkContext.
# Load a text file and convert each line to a Row.
from pyspark.sql import Row
# Text file RDDs can be created using SparkContext’s textFile method.
lines = sc.textFile("file:///opt/apps/SPARK3/spark-3.3.1-hadoop3.2-1.0.4/examples/src/main/resources/people.txt")
parts = lines.map(lambda l: l.split(","))
people = parts.map(lambda p: Row(name=p[0], age=int(p[1])))
people
PythonRDD[5] at RDD at PythonRDD.scala:53
# Infer the schema, and register the DataFrame as a table.
schemaPeople = spark.createDataFrame(people)
schemaPeople.show()
[Stage 1:> (0 + 1) / 1]
+-------+---+ | name|age| +-------+---+ |Michael| 29| | Andy| 30| | Justin| 19| +-------+---+
# SQL can be run over DataFrames that have been registered as a table.
schemaPeople.createOrReplaceTempView("people")
teenagers = spark.sql("SELECT name, age FROM people WHERE age >= 13 AND age <= 19")
teenagers.show()
+------+---+ | name|age| +------+---+ |Justin| 19| +------+---+
Create Spark DataFrame directly from a file¶
sdf = spark.read.csv("file:///opt/apps/SPARK3/spark-3.3.1-hadoop3.2-1.0.4/examples/src/main/resources/people.csv")
sdf.show() # Displays the content of the DataFrame to stdout
+------------------+ | _c0| +------------------+ | name;age;job| |Jorge;30;Developer| | Bob;32;Developer| +------------------+
sdf2 = spark.read.json("file:///opt/apps/SPARK3/spark-3.3.1-hadoop3.2-1.0.4/examples/src/main/resources/people.json")
# Displays the content of the DataFrame to stdout
sdf2.show()
+----+-------+ | age| name| +----+-------+ |null|Michael| | 30| Andy| | 19| Justin| +----+-------+
The CSV file dose not have a header of the data, but we could create a description (schema in Spark) for it .
# Import data types
from pyspark.sql.types import *
# The schema is encoded in a string.
# Create a schema
schemaString = ["name", "age"]
fields = [StructField(field_name, StringType(), True) for field_name in schemaString]
schema = StructType(fields)
schema
StructType([StructField('name', StringType(), True), StructField('age', StringType(), True)])
sdf_withschema = spark.createDataFrame(people, schema)
sdf_withschema.show()
+-------+---+ | name|age| +-------+---+ |Michael| 29| | Andy| 30| | Justin| 19| +-------+---+
Export DataFrame to a local disk¶
sdf.write.mode('overwrite').csv("myspark/")
import os
os.listdir("myspark")
['._SUCCESS.crc', '_SUCCESS']
Read file and infer the schema from the header¶
## Load a local file
air0 = spark.read.options(header='true', inferSchema='true').csv("/data/airdelay_small.csv")
air0
DataFrame[_c0: int, Year: int, Month: int, DayofMonth: int, DayOfWeek: int, DepTime: double, CRSDepTime: int, ArrTime: double, CRSArrTime: int, UniqueCarrier: string, FlightNum: int, TailNum: string, ActualElapsedTime: double, CRSElapsedTime: double, AirTime: double, ArrDelay: double, DepDelay: double, Origin: string, Dest: string, Distance: int, TaxiIn: double, TaxiOut: double, Cancelled: int, CancellationCode: string, Diverted: int, CarrierDelay: double, WeatherDelay: double, NASDelay: double, SecurityDelay: double, LateAircraftDelay: double]
The air delay data contains 5548755 rows with some of the following attributes.
Attribute | Field / Description |
---|---|
Year | Year of flight |
Month | Month of flight |
DayofMonth | Day of month |
DayOfWeek | Day of the week (in number) |
FlightDate | Date on which the flight took place |
UniqueCarrier | Unique Carrier Code. When the same code has been used by multiple carriers, a numeric suffix is used for earlier users, for example, PA, PA(1), PA(2). |
Carrier | Code assigned by IATA and commonly used to identify a carrier. As the same code may have been assigned to different carriers over time, the code is not always unique. |
OriginAirportID | Origin Airport, Airport ID. An identification number assigned by US DOT to identify a unique airport. |
Origin | Origin Airport |
OriginState | Origin Airport, State Code |
DestAirportID | Destination Airport, Airport ID. An identification number assigned by US DOT to identify a unique airport |
Destination | Destination Airport |
DestState | Destination Airport, State Code |
DepTime | Actual Departure Time (local time: hhmm) |
DepDelay | Difference in minutes between scheduled and actual departure time. Early departures show negative numbers. |
ArrTime | Actual Arrival Time (local time: hhmm) |
Cancelled | Cancelled Flight Indicator (1=Yes) |
Distance | Distance between airports (miles) |
CancellationCode | Specifies The Reason For Cancellation |
CarrierDelay | Carrier Delay, in Minutes Weather Delay, in Minutes |
WeatherDelay | Weather DelayLate Aircraft Delay, in Minutes, in Minutes |
NASDelay | National Air System Delay, in Minutes |
SecurityDelay | Security Delay, in Minutes |
LateAircraftDelay | Late Aircraft Delay, in Minutes |
FirstDepTime | First Gate Departure Time at Origin Airport |
TotalAddGTime | Total Ground Time Away from Gate for Gate Return or Cancelled Flight |
LongestAddGTime | Longest Time Away from Gate for Gate Return or Cancelled Flight |
# We specify the correct schema by hand
from pyspark.sql.types import *
schema_sdf = StructType([
StructField('Year', IntegerType(), True),
StructField('Month', IntegerType(), True),
StructField('DayofMonth', IntegerType(), True),
StructField('DayOfWeek', IntegerType(), True),
StructField('DepTime', DoubleType(), True),
StructField('CRSDepTime', DoubleType(), True),
StructField('ArrTime', DoubleType(), True),
StructField('CRSArrTime', DoubleType(), True),
StructField('UniqueCarrier', StringType(), True),
StructField('FlightNum', StringType(), True),
StructField('TailNum', StringType(), True),
StructField('ActualElapsedTime', DoubleType(), True),
StructField('CRSElapsedTime', DoubleType(), True),
StructField('AirTime', DoubleType(), True),
StructField('ArrDelay', DoubleType(), True),
StructField('DepDelay', DoubleType(), True),
StructField('Origin', StringType(), True),
StructField('Dest', StringType(), True),
StructField('Distance', DoubleType(), True),
StructField('TaxiIn', DoubleType(), True),
StructField('TaxiOut', DoubleType(), True),
StructField('Cancelled', IntegerType(), True),
StructField('CancellationCode', StringType(), True),
StructField('Diverted', IntegerType(), True),
StructField('CarrierDelay', DoubleType(), True),
StructField('WeatherDelay', DoubleType(), True),
StructField('NASDelay', DoubleType(), True),
StructField('SecurityDelay', DoubleType(), True),
StructField('LateAircraftDelay', DoubleType(), True)
])
air = spark.read.options(header='true').schema(schema_sdf).csv("/data/airdelay_small.csv")
air
DataFrame[Year: int, Month: int, DayofMonth: int, DayOfWeek: int, DepTime: double, CRSDepTime: double, ArrTime: double, CRSArrTime: double, UniqueCarrier: string, FlightNum: string, TailNum: string, ActualElapsedTime: double, CRSElapsedTime: double, AirTime: double, ArrDelay: double, DepDelay: double, Origin: string, Dest: string, Distance: double, TaxiIn: double, TaxiOut: double, Cancelled: int, CancellationCode: string, Diverted: int, CarrierDelay: double, WeatherDelay: double, NASDelay: double, SecurityDelay: double, LateAircraftDelay: double]
Descriptive Statistics¶
air.describe().show()
[Stage 14:==================================================> (7 + 1) / 8]
+-------+------------------+-------+------------------+------------------+------------------+------------------+------------------+-----------------+------------------+---------+------------------+-----------------+------------------+-----------------+------------------+------------------+------------------+-------+--------+-----------------+-----------------+---------+--------------------+--------+--------------------+------------------+------------------+------------------+-------------------+ |summary| Year| Month| DayofMonth| DayOfWeek| DepTime| CRSDepTime| ArrTime| CRSArrTime| UniqueCarrier|FlightNum| TailNum|ActualElapsedTime| CRSElapsedTime| AirTime| ArrDelay| DepDelay| Origin| Dest|Distance| TaxiIn| TaxiOut|Cancelled| CancellationCode|Diverted| CarrierDelay| WeatherDelay| NASDelay| SecurityDelay| LateAircraftDelay| +-------+------------------+-------+------------------+------------------+------------------+------------------+------------------+-----------------+------------------+---------+------------------+-----------------+------------------+-----------------+------------------+------------------+------------------+-------+--------+-----------------+-----------------+---------+--------------------+--------+--------------------+------------------+------------------+------------------+-------------------+ | count| 1936758|1936758| 1936758| 1936758| 1936758| 1936758| 1936758| 1929648| 1936758| 1936758| 1936758| 0| 1928371| 1936560| 1928371| 1928371| 1936758|1936758| 0| 1936758| 1929648| 0| 1936758| 0| 1936758| 1247488| 1247488| 1247488| 1247488| | mean|3341651.1513358923| 2008.0| 6.11110629206127|15.753470490376186|3.9848272215733718|1518.5341168075722|1467.4726439751378|1610.140628757162| 1634.224640868916| null|2184.2632362948802| null|133.30586334268665|134.3027440409799|108.27714739539228| 42.19988477321014|43.185176464999756| null| null|765.6861590348407|6.812975216205236| null|3.268348446217854...| null|0.004003597764924684|19.179398920069772|3.7035706956700185|15.021635478657911|0.09013713959573158| | stddev|2066064.9575204102| 0.0|3.4825463936659435| 8.776272060384331|1.9959662750518123| 450.4852547937602|424.76679957727623|548.1781425365606|464.63471199067936| null|1944.7022503716598| null| 72.06006897518158|71.34143888170358| 68.64261013867609|56.784715137322074| 53.40250234365981| null| null|574.4796530720843|5.273595064525692| null| 0.01807562425767471| null| 0.06314721711010744|43.546207245474704|21.492900484109036| 33.83305216365375| 2.0227140475056062| | min| 0| 2008| 1| 1| 1.0| 1.0| 0.0| 1.0| 0| 9E| 1| null| 14.0| -25.0| 0.0| -109.0| 10.0| ABE| null| 11.0| 0.0| null| 0| null| 0.0| 0.0| 0.0| 0.0| 0.0| | max| 7009727| 2008| 12| 31| 7.0| 2400.0| 2359.0| 2400.0| 959| YV| 999| null| 1114.0| 660.0| 1091.0| 2461.0| 999.0| YUM| null| 4962.0| 240.0| null| 1| null| 1.0| 2436.0| 1352.0| 1357.0| 392.0| +-------+------------------+-------+------------------+------------------+------------------+------------------+------------------+-----------------+------------------+---------+------------------+-----------------+------------------+-----------------+------------------+------------------+------------------+-------+--------+-----------------+-----------------+---------+--------------------+--------+--------------------+------------------+------------------+------------------+-------------------+
23/11/22 11:58:00 WARN [Thread-6] package: Truncated the string representation of a plan since it was too large. This behavior can be adjusted by setting 'spark.sql.debug.maxToStringFields'.
air.describe(['ArrDelay']).show()
[Stage 5:> (0 + 8) / 8]
+-------+------------------+ |summary| ArrDelay| +-------+------------------+ | count| 1928371| | mean|108.27714739539228| | stddev| 68.64261013867609| | min| 0.0| | max| 1091.0| +-------+------------------+
Print the schema in a tree format¶
air.printSchema()
root |-- Year: integer (nullable = true) |-- Month: integer (nullable = true) |-- DayofMonth: integer (nullable = true) |-- DayOfWeek: integer (nullable = true) |-- DepTime: double (nullable = true) |-- CRSDepTime: double (nullable = true) |-- ArrTime: double (nullable = true) |-- CRSArrTime: double (nullable = true) |-- UniqueCarrier: string (nullable = true) |-- FlightNum: string (nullable = true) |-- TailNum: string (nullable = true) |-- ActualElapsedTime: double (nullable = true) |-- CRSElapsedTime: double (nullable = true) |-- AirTime: double (nullable = true) |-- ArrDelay: double (nullable = true) |-- DepDelay: double (nullable = true) |-- Origin: string (nullable = true) |-- Dest: string (nullable = true) |-- Distance: double (nullable = true) |-- TaxiIn: double (nullable = true) |-- TaxiOut: double (nullable = true) |-- Cancelled: integer (nullable = true) |-- CancellationCode: string (nullable = true) |-- Diverted: integer (nullable = true) |-- CarrierDelay: double (nullable = true) |-- WeatherDelay: double (nullable = true) |-- NASDelay: double (nullable = true) |-- SecurityDelay: double (nullable = true) |-- LateAircraftDelay: double (nullable = true)
Select columns¶
air.select(["ArrDelay","AirTime","Distance"]).show()
+--------+-------+--------+ |ArrDelay|AirTime|Distance| +--------+-------+--------+ | 2.0| 25.0| 127.0| | 29.0| 248.0| 1623.0| | 8.0| null| 622.0| | -2.0| 70.0| 451.0| | 11.0| 133.0| 1009.0| | 13.0| 177.0| 1562.0| | -12.0| 181.0| 1589.0| | 11.0| 364.0| 2611.0| | 13.0| 53.0| 304.0| | 9.0| null| 888.0| | -8.0| 293.0| 2537.0| | 15.0| null| 1723.0| | -14.0| null| 1736.0| | 55.0| 285.0| 1927.0| | 23.0| 149.0| 991.0| | 64.0| 35.0| 193.0| | 29.0| 25.0| 77.0| | -8.0| null| 447.0| | -6.0| 91.0| 678.0| | 35.0| 127.0| 998.0| +--------+-------+--------+ only showing top 20 rows
air.select(air['UniqueCarrier'], air['ArrDelay']>0).show()
+-------------+--------------+ |UniqueCarrier|(ArrDelay > 0)| +-------------+--------------+ | XE| true| | CO| true| | AA| true| | WN| false| | CO| true| | AA| true| | DL| false| | AA| true| | US| true| | AA| true| | AS| false| | UA| true| | TW| false| | NW| true| | NW| true| | AA| true| | DH| true| | WN| false| | AA| false| | CO| true| +-------------+--------------+ only showing top 20 rows
# group data with respect to some columns
air.groupBy(["UniqueCarrier","DayOfWeek"]).count().show()
+-------------+---------+------+ |UniqueCarrier|DayOfWeek| count| +-------------+---------+------+ | PS| 6| 406| | CO| 4| 55764| | ML (1)| 7| 442| | XE| 4| 14896| | TZ| 4| 1455| | OO| 3| 17310| | EA| 7| 6197| | OO| 4| 17666| | F9| 2| 1679| | HA| 5| 1519| | EA| 5| 6295| | UA| 4| 89272| | EV| 4| 9729| | DL| 6|106031| | FL| 5| 6962| | YV| 3| 4165| | AQ| 2| 1035| | ML (1)| 2| 502| | DL| 3|110827| | YV| 6| 3828| +-------------+---------+------+ only showing top 20 rows
## Group and sort
aircount=air.groupBy("UniqueCarrier").count()
aircount.sort("count",ascending=False).show()
[Stage 38:=============================> (4 + 4) / 8]
+-------------+------+ |UniqueCarrier| count| +-------------+------+ | DL|765388| | WN|703368| | AA|684522| | US|649056| | UA|611957| | NW|473820| | CO|373858| | TW|179081| | HP|173509| | MQ|164790| | AS|129863| | OO|120223| | XE| 94311| | EV| 67148| | OH| 60630| | FL| 47540| | EA| 43723| | PI| 41489| | DH| 32900| | B6| 29111| +-------------+------+ only showing top 20 rows
Data cleaning¶
## Returns a new DataFrame omitting rows with null values
air_without_na = air.na.drop()
air_without_na.show()
[Stage 43:======================================> (2 + 1) / 3]
+----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |Year|Month|DayofMonth|DayOfWeek|DepTime|CRSDepTime|ArrTime|CRSArrTime|UniqueCarrier|FlightNum|TailNum|ActualElapsedTime|CRSElapsedTime|AirTime|ArrDelay|DepDelay|Origin|Dest|Distance|TaxiIn|TaxiOut|Cancelled|CancellationCode|Diverted|CarrierDelay|WeatherDelay|NASDelay|SecurityDelay|LateAircraftDelay| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+
air_without_na.count()
0
air.count() # original file size
5548754
air.show()
+----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |Year|Month|DayofMonth|DayOfWeek|DepTime|CRSDepTime|ArrTime|CRSArrTime|UniqueCarrier|FlightNum|TailNum|ActualElapsedTime|CRSElapsedTime|AirTime|ArrDelay|DepDelay|Origin|Dest|Distance|TaxiIn|TaxiOut|Cancelled|CancellationCode|Diverted|CarrierDelay|WeatherDelay|NASDelay|SecurityDelay|LateAircraftDelay| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |2006| 7| 6| 4| 2055.0| 2055.0| 2150.0| 2148.0| XE| 2619| N11526| 55.0| 53.0| 25.0| 2.0| 0.0| IAH| LCH| 127.0| 8.0| 22.0| 0| null| 0| 0.0| 0.0| 0.0| 0.0| 0.0| |1997| 3| 2| 7| 2019.0| 2015.0| 2314.0| 2245.0| CO| 143| N59302| 295.0| 270.0| 248.0| 29.0| 4.0| EWR| COS| 1623.0| 6.0| 41.0| 0| NA| 0| null| null| null| null| null| |1994| 5| 2| 1| 700.0| 700.0| 804.0| 756.0| AA| 1629| NA| 124.0| 116.0| null| 8.0| 0.0| BWI| ORD| 622.0| null| null| 0| NA| 0| null| null| null| null| null| |1997| 2| 14| 5| 700.0| 700.0| 728.0| 730.0| WN| 1783| N332| 88.0| 90.0| 70.0| -2.0| 0.0| TUS| LAX| 451.0| 8.0| 10.0| 0| NA| 0| null| null| null| null| null| |2000| 6| 11| 7| 2052.0| 2034.0| 2132.0| 2121.0| CO| 1753| N16893| 160.0| 167.0| 133.0| 11.0| 18.0| IAH| PHX| 1009.0| 5.0| 22.0| 0| NA| 0| null| null| null| null| null| |1997| 11| 16| 7| 1503.0| 1414.0| 1912.0| 1859.0| AA| 414| N205AA| 189.0| 225.0| 177.0| 13.0| 49.0| DFW| BOS| 1562.0| 4.0| 8.0| 0| NA| 0| null| null| null| null| null| |1999| 5| 31| 1| 839.0| 845.0| 1409.0| 1421.0| DL| 152| N177DZ| 210.0| 216.0| 181.0| -12.0| -6.0| SLC| ATL| 1589.0| 11.0| 18.0| 0| NA| 0| null| null| null| null| null| |1997| 4| 30| 3| 828.0| 830.0| 1206.0| 1155.0| AA| 11| N5DAAA| 398.0| 385.0| 364.0| 11.0| -2.0| BOS| LAX| 2611.0| 5.0| 29.0| 0| NA| 0| null| null| null| null| null| |1995| 7| 21| 5| 1018.0| 1000.0| 1126.0| 1113.0| US| 272| N274US| 68.0| 73.0| 53.0| 13.0| 18.0| GSO| PIT| 304.0| 4.0| 11.0| 0| NA| 0| null| null| null| null| null| |1989| 9| 28| 4| 1501.0| 1450.0| 1639.0| 1630.0| AA| 905| NA| 158.0| 160.0| null| 9.0| 11.0| ORD| DEN| 888.0| null| null| 0| NA| 0| null| null| null| null| null| |2007| 10| 26| 5| 654.0| 700.0| 1507.0| 1515.0| AS| 802| N648AS| 313.0| 315.0| 293.0| -8.0| -6.0| PDX| BOS| 2537.0| 9.0| 11.0| 0| null| 0| 0.0| 0.0| 0.0| 0.0| 0.0| |1993| 6| 28| 1| 1540.0| 1541.0| 2146.0| 2131.0| UA| 1746| NA| 246.0| 230.0| null| 15.0| -1.0| SAN| ORD| 1723.0| null| null| 0| NA| 0| null| null| null| null| null| |1994| 3| 31| 4| 1909.0| 1900.0| 2116.0| 2130.0| TW| 819| NA| 247.0| 270.0| null| -14.0| 9.0| STL| SFO| 1736.0| null| null| 0| NA| 0| null| null| null| null| null| |2000| 5| 23| 2| 958.0| 910.0| 1205.0| 1110.0| NW| 281| N523US| 307.0| 300.0| 285.0| 55.0| 48.0| DTW| SEA| 1927.0| 8.0| 14.0| 0| NA| 0| null| null| null| null| null| |2004| 10| 18| 1| 939.0| 940.0| 1151.0| 1128.0| NW| 679| N317NB| 192.0| 168.0| 149.0| 23.0| -1.0| MSP| SLC| 991.0| 10.0| 33.0| 0| null| 0| 0.0| 0.0| 23.0| 0.0| 0.0| |2007| 5| 17| 4| 1944.0| 1830.0| 2034.0| 1930.0| AA| 1011| N3BDAA| 50.0| 60.0| 35.0| 64.0| 74.0| MIA| MCO| 193.0| 4.0| 11.0| 0| null| 0| 64.0| 0.0| 0.0| 0.0| 0.0| |2003| 7| 31| 4| 1738.0| 1710.0| 1819.0| 1750.0| DH| 7981| N309UE| 41.0| 40.0| 25.0| 29.0| 28.0| IAD| CHO| 77.0| 3.0| 12.0| 0| null| 0| 29.0| 0.0| 0.0| 0.0| 0.0| |1993| 3| 17| 3| 630.0| 630.0| 747.0| 755.0| WN| 1968| NA| 77.0| 85.0| null| -8.0| 0.0| SFO| SAN| 447.0| null| null| 0| NA| 0| null| null| null| null| null| |2002| 8| 25| 7| 1255.0| 1250.0| 1552.0| 1558.0| AA| 768| N464AA| 117.0| 128.0| 91.0| -6.0| 5.0| ORD| PHL| 678.0| 7.0| 19.0| 0| NA| 0| null| null| null| null| null| |1995| 7| 30| 7| 2018.0| 1955.0| 2318.0| 2243.0| CO| 765| N578PE| 180.0| 168.0| 127.0| 35.0| 23.0| EWR| TPA| 998.0| 3.0| 50.0| 0| NA| 0| null| null| null| null| null| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ only showing top 20 rows
## Replace null values
air.na.fill("unknown").show()
+----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |Year|Month|DayofMonth|DayOfWeek|DepTime|CRSDepTime|ArrTime|CRSArrTime|UniqueCarrier|FlightNum|TailNum|ActualElapsedTime|CRSElapsedTime|AirTime|ArrDelay|DepDelay|Origin|Dest|Distance|TaxiIn|TaxiOut|Cancelled|CancellationCode|Diverted|CarrierDelay|WeatherDelay|NASDelay|SecurityDelay|LateAircraftDelay| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |2006| 7| 6| 4| 2055.0| 2055.0| 2150.0| 2148.0| XE| 2619| N11526| 55.0| 53.0| 25.0| 2.0| 0.0| IAH| LCH| 127.0| 8.0| 22.0| 0| unknown| 0| 0.0| 0.0| 0.0| 0.0| 0.0| |1997| 3| 2| 7| 2019.0| 2015.0| 2314.0| 2245.0| CO| 143| N59302| 295.0| 270.0| 248.0| 29.0| 4.0| EWR| COS| 1623.0| 6.0| 41.0| 0| NA| 0| null| null| null| null| null| |1994| 5| 2| 1| 700.0| 700.0| 804.0| 756.0| AA| 1629| NA| 124.0| 116.0| null| 8.0| 0.0| BWI| ORD| 622.0| null| null| 0| NA| 0| null| null| null| null| null| |1997| 2| 14| 5| 700.0| 700.0| 728.0| 730.0| WN| 1783| N332| 88.0| 90.0| 70.0| -2.0| 0.0| TUS| LAX| 451.0| 8.0| 10.0| 0| NA| 0| null| null| null| null| null| |2000| 6| 11| 7| 2052.0| 2034.0| 2132.0| 2121.0| CO| 1753| N16893| 160.0| 167.0| 133.0| 11.0| 18.0| IAH| PHX| 1009.0| 5.0| 22.0| 0| NA| 0| null| null| null| null| null| |1997| 11| 16| 7| 1503.0| 1414.0| 1912.0| 1859.0| AA| 414| N205AA| 189.0| 225.0| 177.0| 13.0| 49.0| DFW| BOS| 1562.0| 4.0| 8.0| 0| NA| 0| null| null| null| null| null| |1999| 5| 31| 1| 839.0| 845.0| 1409.0| 1421.0| DL| 152| N177DZ| 210.0| 216.0| 181.0| -12.0| -6.0| SLC| ATL| 1589.0| 11.0| 18.0| 0| NA| 0| null| null| null| null| null| |1997| 4| 30| 3| 828.0| 830.0| 1206.0| 1155.0| AA| 11| N5DAAA| 398.0| 385.0| 364.0| 11.0| -2.0| BOS| LAX| 2611.0| 5.0| 29.0| 0| NA| 0| null| null| null| null| null| |1995| 7| 21| 5| 1018.0| 1000.0| 1126.0| 1113.0| US| 272| N274US| 68.0| 73.0| 53.0| 13.0| 18.0| GSO| PIT| 304.0| 4.0| 11.0| 0| NA| 0| null| null| null| null| null| |1989| 9| 28| 4| 1501.0| 1450.0| 1639.0| 1630.0| AA| 905| NA| 158.0| 160.0| null| 9.0| 11.0| ORD| DEN| 888.0| null| null| 0| NA| 0| null| null| null| null| null| |2007| 10| 26| 5| 654.0| 700.0| 1507.0| 1515.0| AS| 802| N648AS| 313.0| 315.0| 293.0| -8.0| -6.0| PDX| BOS| 2537.0| 9.0| 11.0| 0| unknown| 0| 0.0| 0.0| 0.0| 0.0| 0.0| |1993| 6| 28| 1| 1540.0| 1541.0| 2146.0| 2131.0| UA| 1746| NA| 246.0| 230.0| null| 15.0| -1.0| SAN| ORD| 1723.0| null| null| 0| NA| 0| null| null| null| null| null| |1994| 3| 31| 4| 1909.0| 1900.0| 2116.0| 2130.0| TW| 819| NA| 247.0| 270.0| null| -14.0| 9.0| STL| SFO| 1736.0| null| null| 0| NA| 0| null| null| null| null| null| |2000| 5| 23| 2| 958.0| 910.0| 1205.0| 1110.0| NW| 281| N523US| 307.0| 300.0| 285.0| 55.0| 48.0| DTW| SEA| 1927.0| 8.0| 14.0| 0| NA| 0| null| null| null| null| null| |2004| 10| 18| 1| 939.0| 940.0| 1151.0| 1128.0| NW| 679| N317NB| 192.0| 168.0| 149.0| 23.0| -1.0| MSP| SLC| 991.0| 10.0| 33.0| 0| unknown| 0| 0.0| 0.0| 23.0| 0.0| 0.0| |2007| 5| 17| 4| 1944.0| 1830.0| 2034.0| 1930.0| AA| 1011| N3BDAA| 50.0| 60.0| 35.0| 64.0| 74.0| MIA| MCO| 193.0| 4.0| 11.0| 0| unknown| 0| 64.0| 0.0| 0.0| 0.0| 0.0| |2003| 7| 31| 4| 1738.0| 1710.0| 1819.0| 1750.0| DH| 7981| N309UE| 41.0| 40.0| 25.0| 29.0| 28.0| IAD| CHO| 77.0| 3.0| 12.0| 0| unknown| 0| 29.0| 0.0| 0.0| 0.0| 0.0| |1993| 3| 17| 3| 630.0| 630.0| 747.0| 755.0| WN| 1968| NA| 77.0| 85.0| null| -8.0| 0.0| SFO| SAN| 447.0| null| null| 0| NA| 0| null| null| null| null| null| |2002| 8| 25| 7| 1255.0| 1250.0| 1552.0| 1558.0| AA| 768| N464AA| 117.0| 128.0| 91.0| -6.0| 5.0| ORD| PHL| 678.0| 7.0| 19.0| 0| NA| 0| null| null| null| null| null| |1995| 7| 30| 7| 2018.0| 1955.0| 2318.0| 2243.0| CO| 765| N578PE| 180.0| 168.0| 127.0| 35.0| 23.0| EWR| TPA| 998.0| 3.0| 50.0| 0| NA| 0| null| null| null| null| null| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ only showing top 20 rows
air.na.replace('NA', "unknown").show()
+----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |Year|Month|DayofMonth|DayOfWeek|DepTime|CRSDepTime|ArrTime|CRSArrTime|UniqueCarrier|FlightNum|TailNum|ActualElapsedTime|CRSElapsedTime|AirTime|ArrDelay|DepDelay|Origin|Dest|Distance|TaxiIn|TaxiOut|Cancelled|CancellationCode|Diverted|CarrierDelay|WeatherDelay|NASDelay|SecurityDelay|LateAircraftDelay| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |2006| 7| 6| 4| 2055.0| 2055.0| 2150.0| 2148.0| XE| 2619| N11526| 55.0| 53.0| 25.0| 2.0| 0.0| IAH| LCH| 127.0| 8.0| 22.0| 0| null| 0| 0.0| 0.0| 0.0| 0.0| 0.0| |1997| 3| 2| 7| 2019.0| 2015.0| 2314.0| 2245.0| CO| 143| N59302| 295.0| 270.0| 248.0| 29.0| 4.0| EWR| COS| 1623.0| 6.0| 41.0| 0| unknown| 0| null| null| null| null| null| |1994| 5| 2| 1| 700.0| 700.0| 804.0| 756.0| AA| 1629|unknown| 124.0| 116.0| null| 8.0| 0.0| BWI| ORD| 622.0| null| null| 0| unknown| 0| null| null| null| null| null| |1997| 2| 14| 5| 700.0| 700.0| 728.0| 730.0| WN| 1783| N332| 88.0| 90.0| 70.0| -2.0| 0.0| TUS| LAX| 451.0| 8.0| 10.0| 0| unknown| 0| null| null| null| null| null| |2000| 6| 11| 7| 2052.0| 2034.0| 2132.0| 2121.0| CO| 1753| N16893| 160.0| 167.0| 133.0| 11.0| 18.0| IAH| PHX| 1009.0| 5.0| 22.0| 0| unknown| 0| null| null| null| null| null| |1997| 11| 16| 7| 1503.0| 1414.0| 1912.0| 1859.0| AA| 414| N205AA| 189.0| 225.0| 177.0| 13.0| 49.0| DFW| BOS| 1562.0| 4.0| 8.0| 0| unknown| 0| null| null| null| null| null| |1999| 5| 31| 1| 839.0| 845.0| 1409.0| 1421.0| DL| 152| N177DZ| 210.0| 216.0| 181.0| -12.0| -6.0| SLC| ATL| 1589.0| 11.0| 18.0| 0| unknown| 0| null| null| null| null| null| |1997| 4| 30| 3| 828.0| 830.0| 1206.0| 1155.0| AA| 11| N5DAAA| 398.0| 385.0| 364.0| 11.0| -2.0| BOS| LAX| 2611.0| 5.0| 29.0| 0| unknown| 0| null| null| null| null| null| |1995| 7| 21| 5| 1018.0| 1000.0| 1126.0| 1113.0| US| 272| N274US| 68.0| 73.0| 53.0| 13.0| 18.0| GSO| PIT| 304.0| 4.0| 11.0| 0| unknown| 0| null| null| null| null| null| |1989| 9| 28| 4| 1501.0| 1450.0| 1639.0| 1630.0| AA| 905|unknown| 158.0| 160.0| null| 9.0| 11.0| ORD| DEN| 888.0| null| null| 0| unknown| 0| null| null| null| null| null| |2007| 10| 26| 5| 654.0| 700.0| 1507.0| 1515.0| AS| 802| N648AS| 313.0| 315.0| 293.0| -8.0| -6.0| PDX| BOS| 2537.0| 9.0| 11.0| 0| null| 0| 0.0| 0.0| 0.0| 0.0| 0.0| |1993| 6| 28| 1| 1540.0| 1541.0| 2146.0| 2131.0| UA| 1746|unknown| 246.0| 230.0| null| 15.0| -1.0| SAN| ORD| 1723.0| null| null| 0| unknown| 0| null| null| null| null| null| |1994| 3| 31| 4| 1909.0| 1900.0| 2116.0| 2130.0| TW| 819|unknown| 247.0| 270.0| null| -14.0| 9.0| STL| SFO| 1736.0| null| null| 0| unknown| 0| null| null| null| null| null| |2000| 5| 23| 2| 958.0| 910.0| 1205.0| 1110.0| NW| 281| N523US| 307.0| 300.0| 285.0| 55.0| 48.0| DTW| SEA| 1927.0| 8.0| 14.0| 0| unknown| 0| null| null| null| null| null| |2004| 10| 18| 1| 939.0| 940.0| 1151.0| 1128.0| NW| 679| N317NB| 192.0| 168.0| 149.0| 23.0| -1.0| MSP| SLC| 991.0| 10.0| 33.0| 0| null| 0| 0.0| 0.0| 23.0| 0.0| 0.0| |2007| 5| 17| 4| 1944.0| 1830.0| 2034.0| 1930.0| AA| 1011| N3BDAA| 50.0| 60.0| 35.0| 64.0| 74.0| MIA| MCO| 193.0| 4.0| 11.0| 0| null| 0| 64.0| 0.0| 0.0| 0.0| 0.0| |2003| 7| 31| 4| 1738.0| 1710.0| 1819.0| 1750.0| DH| 7981| N309UE| 41.0| 40.0| 25.0| 29.0| 28.0| IAD| CHO| 77.0| 3.0| 12.0| 0| null| 0| 29.0| 0.0| 0.0| 0.0| 0.0| |1993| 3| 17| 3| 630.0| 630.0| 747.0| 755.0| WN| 1968|unknown| 77.0| 85.0| null| -8.0| 0.0| SFO| SAN| 447.0| null| null| 0| unknown| 0| null| null| null| null| null| |2002| 8| 25| 7| 1255.0| 1250.0| 1552.0| 1558.0| AA| 768| N464AA| 117.0| 128.0| 91.0| -6.0| 5.0| ORD| PHL| 678.0| 7.0| 19.0| 0| unknown| 0| null| null| null| null| null| |1995| 7| 30| 7| 2018.0| 1955.0| 2318.0| 2243.0| CO| 765| N578PE| 180.0| 168.0| 127.0| 35.0| 23.0| EWR| TPA| 998.0| 3.0| 50.0| 0| unknown| 0| null| null| null| null| null| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ only showing top 20 rows
Statistics¶
air.corr("Distance","ArrDelay")
0.0024019187216827364
air.cov("Distance","ArrDelay")
39.54483781577919
air.filter(air.ArrDelay > 60).show() # filter with certain conditions
+----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |Year|Month|DayofMonth|DayOfWeek|DepTime|CRSDepTime|ArrTime|CRSArrTime|UniqueCarrier|FlightNum|TailNum|ActualElapsedTime|CRSElapsedTime|AirTime|ArrDelay|DepDelay|Origin|Dest|Distance|TaxiIn|TaxiOut|Cancelled|CancellationCode|Diverted|CarrierDelay|WeatherDelay|NASDelay|SecurityDelay|LateAircraftDelay| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ |2007| 5| 17| 4| 1944.0| 1830.0| 2034.0| 1930.0| AA| 1011| N3BDAA| 50.0| 60.0| 35.0| 64.0| 74.0| MIA| MCO| 193.0| 4.0| 11.0| 0| null| 0| 64.0| 0.0| 0.0| 0.0| 0.0| |2001| 5| 31| 4| 1812.0| 1650.0| 1954.0| 1825.0| WN| 1612| N641@@| 102.0| 95.0| 86.0| 89.0| 82.0| MDW| BHM| 570.0| 3.0| 13.0| 0| NA| 0| null| null| null| null| null| |1999| 8| 13| 5| 1800.0| 1635.0| 2000.0| 1826.0| DL| 965| N404DA| 120.0| 111.0| 97.0| 94.0| 85.0| RSW| ATL| 515.0| 10.0| 13.0| 0| NA| 0| null| null| null| null| null| |2004| 4| 16| 5| 1550.0| 1525.0| 1750.0| 1638.0| XE| 2602| N15948| 120.0| 73.0| 35.0| 72.0| 25.0| EWR| BWI| 169.0| 5.0| 80.0| 0| null| 0| 0.0| 0.0| 51.0| 0.0| 21.0| |1999| 8| 17| 2| 1246.0| 1135.0| 1430.0| 1310.0| CO| 1843| N77303| 104.0| 95.0| 71.0| 80.0| 71.0| EWR| CMH| 462.0| 6.0| 27.0| 0| NA| 0| null| null| null| null| null| |1999| 6| 10| 4| 2214.0| 0.0| 2259.0| 0.0| UA| 1659| N1829U| 105.0| 113.0| 83.0| 101.0| 109.0| BWI| ORD| 622.0| 10.0| 12.0| 0| NA| 0| null| null| null| null| null| |1988| 5| 17| 2| 1714.0| 1516.0| 1938.0| 1739.0| AA| 885| NA| 204.0| 203.0| null| 119.0| 118.0| PHL| DFW| 1302.0| null| null| 0| NA| 0| null| null| null| null| null| |2005| 7| 1| 5| 1931.0| 1723.0| 2235.0| 2017.0| FL| 831| N978AT| 124.0| 114.0| 86.0| 138.0| 128.0| MDW| ATL| 590.0| 9.0| 29.0| 0| null| 0| 0.0| 0.0| 10.0| 0.0| 128.0| |2005| 11| 22| 2| 1849.0| 1705.0| 2034.0| 1815.0| B6| 55| N585JB| 105.0| 70.0| 56.0| 139.0| 104.0| BTV| JFK| 267.0| 4.0| 45.0| 0| null| 0| 0.0| 0.0| 35.0| 0.0| 104.0| |1998| 6| 14| 7| 2015.0| 1820.0| 2058.0| 1924.0| NW| 1267| N715RC| 103.0| 124.0| 85.0| 94.0| 115.0| CLE| MSP| 622.0| 7.0| 11.0| 0| NA| 0| null| null| null| null| null| |2007| 10| 21| 7| 1725.0| 1625.0| 1837.0| 1730.0| WN| 143| N389SW| 72.0| 65.0| 42.0| 67.0| 60.0| LAS| LAX| 236.0| 12.0| 18.0| 0| null| 0| 0.0| 0.0| 7.0| 0.0| 60.0| |2005| 4| 15| 5| 1519.0| 1310.0| 1751.0| 1545.0| AS| 631| N947AS| 152.0| 155.0| 136.0| 126.0| 129.0| LAS| SEA| 866.0| 5.0| 11.0| 0| null| 0| 4.0| 0.0| 0.0| 0.0| 122.0| |2003| 3| 13| 4| 1947.0| 1845.0| 2057.0| 1942.0| XE| 2736| N16520| 70.0| 57.0| 38.0| 75.0| 62.0| IAH| SHV| 192.0| 8.0| 24.0| 0| NA| 0| null| null| null| null| null| |2006| 1| 24| 2| 1230.0| 1115.0| 1343.0| 1228.0| OH| 5050| N784CA| 73.0| 73.0| 50.0| 75.0| 75.0| JFK| BOS| 187.0| 5.0| 18.0| 0| null| 0| 75.0| 0.0| 0.0| 0.0| 0.0| |2007| 6| 16| 6| 1525.0| 1155.0| 1636.0| 1255.0| XE| 2317| N14933| 71.0| 60.0| 44.0| 221.0| 210.0| LFT| IAH| 201.0| 10.0| 17.0| 0| null| 0| 0.0| 0.0| 104.0| 0.0| 117.0| |1990| 9| 18| 2| 1351.0| 1245.0| 1445.0| 1325.0| US| 2901| NA| 54.0| 40.0| null| 80.0| 66.0| SEA| BLI| 94.0| null| null| 0| NA| 0| null| null| null| null| null| |1996| 9| 9| 1| 2135.0| 1955.0| 2247.0| 2114.0| US| 866| N351US| 72.0| 79.0| 52.0| 93.0| 100.0| LGA| RIC| 292.0| 10.0| 10.0| 0| NA| 0| null| null| null| null| null| |2006| 12| 1| 5| 1016.0| 720.0| 1226.0| 925.0| MQ| 3484| N902BC| 190.0| 185.0| 167.0| 181.0| 176.0| CHS| DFW| 987.0| 11.0| 12.0| 0| null| 0| 176.0| 0.0| 5.0| 0.0| 0.0| |1997| 12| 29| 1| 2349.0| 2200.0| 159.0| 2345.0| US| 634| N408US| 130.0| 105.0| 115.0| 134.0| 109.0| CLT| EWR| 529.0| 6.0| 9.0| 0| NA| 0| null| null| null| null| null| |2007| 8| 25| 6| 1544.0| 1430.0| 2123.0| 2015.0| AA| 2073| N612AA| 279.0| 285.0| 256.0| 68.0| 74.0| ORD| SJU| 2072.0| 4.0| 19.0| 0| null| 0| 68.0| 0.0| 0.0| 0.0| 0.0| +----+-----+----------+---------+-------+----------+-------+----------+-------------+---------+-------+-----------------+--------------+-------+--------+--------+------+----+--------+------+-------+---------+----------------+--------+------------+------------+--------+-------------+-----------------+ only showing top 20 rows
User-defined functions¶
## air2 = air.select(["DayOfWeek","ArrDelay","AirTime","Distance"])
air2_pdf = air.select(["DayOfWeek", "ArrDelay","AirTime","Distance"]).toPandas()
air2_pdf
DayOfWeek | ArrDelay | AirTime | Distance | |
---|---|---|---|---|
0 | 4 | 2.0 | 25.0 | 127.0 |
1 | 7 | 29.0 | 248.0 | 1623.0 |
2 | 1 | 8.0 | NaN | 622.0 |
3 | 5 | -2.0 | 70.0 | 451.0 |
4 | 7 | 11.0 | 133.0 | 1009.0 |
... | ... | ... | ... | ... |
5548749 | 3 | 13.0 | 59.0 | 318.0 |
5548750 | 1 | 22.0 | 34.0 | 181.0 |
5548751 | 1 | 11.0 | 71.0 | 551.0 |
5548752 | 2 | -1.0 | NaN | 288.0 |
5548753 | 2 | -14.0 | 107.0 | 888.0 |
5548754 rows × 4 columns
import pandas as pd
def myfun(pdf):
out = dict()
out["ArrDelay"] = pdf.ArrDelay.mean()
out["AirTime"] = pdf.AirTime.mean()
out["Distance"] = pdf.Distance.mean()
return pd.DataFrame(out, index=[0])
myfun(air2_pdf)
ArrDelay | AirTime | Distance | |
---|---|---|---|
0 | 6.97898 | 102.682434 | 700.156953 |