copy D:\deploy\hadoop-3.0.0\bin\hadoop.dll C:\Windows\System32

pip install pyspark==3.2.1

>java -version
java version "1.8.0_201"
Java(TM) SE Runtime Environment (build 1.8.0_201-b09)
Java HotSpot(TM) 64-Bit Server VM (build 25.201-b09, mixed mode)

pip install graphframes==0.6

C:\Users\ASUS>pip show pyspark
Name: pyspark
Version: 3.2.1
Summary: Apache Spark Python API
Home-page: https://github.com/apache/spark/tree/master/python
Author: Spark Developers
Author-email: dev@spark.apache.org
License: http://www.apache.org/licenses/LICENSE-2.0
Location: d:\miniconda3\lib\site-packages
Requires: py4j
Required-by:

from pyspark.sql import SparkSession, Row

spark = SparkSession \
    .builder \
    .appName("Python Spark") \
    .master("local[*]") \
    .getOrCreate()
sc = spark.sparkContext
spark

from pyspark.sql import SparkSession
from pyspark.sql import Row

spark = SparkSession \
    .builder \
    .appName("Python Spark SQL Hive integration example") \
    .enableHiveSupport() \
    .getOrCreate()
sc = spark.sparkContext
spark

>winutils ls \tmp\hive
drwx------ 1 BUILTIN\Administrators XIAOXIAOMING\None 0 May  4 2020 \tmp\hive

>winutils chmod 777 \tmp\hive

>winutils ls \tmp\hive
drwxrwxrwx 1 BUILTIN\Administrators XIAOXIAOMING\None 0 May  4 2020 \tmp\hive

//查看DataFrame中的內(nèi)容
df.show()

//查看DataFrame部分列中的內(nèi)容
df.select(df['name'], df['age'] + 1).show()
df.select("name").show()
//打印DataFrame的Schema信息
df.printSchema()
//過濾age大于等于 21 的
df.filter(df['age'] > 21).show()
//按年齡進行分組并統(tǒng)計相同年齡的人數(shù)
personDF.groupBy("age").count().show()

df.createOrReplaceTempView("people")
//df.createTempView("t_person")

//查詢年齡最大的前兩名
spark.sql("select * from t_person order by age desc limit 2").show()
//顯示表的Schema信息
spark.sql("desc t_person").show()

strlen = spark.udf.register("len", lambda x: len(x))
print(spark.sql("SELECT len('test') length").collect())
print(spark.sql("SELECT 'foo' AS text").select(strlen("text").alias('length')).collect())

@Experimental
def combineByKeyWithClassTag[C](
    createCombiner: V => C,
    mergeValue: (C, V) => C,
    mergeCombiners: (C, C) => C)(implicit ct: ClassTag[C]): RDD[(K, C)] = self.withScope {
  combineByKeyWithClassTag(createCombiner,mergeValue,mergeCombiners
       ,defaultPartitioner(self))
}
def combineByKey[C](
    createCombiner: V => C,
    mergeValue: (C, V) => C,
    mergeCombiners: (C, C) => C): RDD[(K, C)] = self.withScope {
  combineByKeyWithClassTag(createCombiner, mergeValue, mergeCombiners)(null)
}
def groupByKey(partitioner: Partitioner): RDD[(K, Iterable[V])] = self.withScope {
  val createCombiner = (v: V) => CompactBuffer(v)
  val mergeValue = (buf: CompactBuffer[V], v: V) => buf += v
  val mergeCombiners = (c1: CompactBuffer[V], c2: CompactBuffer[V]) => c1 ++= c2
  val bufs = combineByKeyWithClassTag[CompactBuffer[V]](
    createCombiner, mergeValue, mergeCombiners, partitioner, mapSideCombine = false)
  bufs.asInstanceOf[RDD[(K, Iterable[V])]]
}

val a = sc.parallelize(List("dog", "tiger", "lion", "cat", "spider", "eagle"), 2).keyBy(_.length)
a.groupByKey.collect

res9: Array[(Int, Iterable[String])] = Array((4,CompactBuffer(lion)), (6,CompactBuffer(spider)), (3,CompactBuffer(dog, cat)), (5,CompactBuffer(tiger, eagle)))

val pairRDD = sc.parallelize(List( ("cat",2), ("cat", 5), ("mouse", 4),("cat", 12), ("dog", 12), ("mouse", 2)), 2)
pairRDD.aggregateByKey(0)(math.max(_, _), _ + _).collect
res6: Array[(String, Int)] = Array((dog,12), (cat,17), (mouse,6))
pairRDD.aggregateByKey(100)(math.max(_, _), _ + _).collect
res7: Array[(String, Int)] = Array((dog,100), (cat,200), (mouse,200))

val a = sc.parallelize(List("dog", "tiger", "lion", "cat", "panther", "eagle"), 2)
val b = a.map(x => (x.length, x))
b.reduceByKey(_ + _).collect

object MapreduceWordcount {
  def main(args: Array[String]): Unit = {
    import org.apache.spark._
    val sc: SparkContext = new SparkContext(new SparkConf().setAppName("wordcount").setMaster("local[*]"))
    sc.setLogLevel("WARN")
    
    import org.apache.hadoop.io.{LongWritable, Text}
    import org.apache.hadoop.mapred.TextInputFormat
    import org.apache.spark.rdd.HadoopRDD

    import scala.collection.mutable.ArrayBuffer
    
    def map(k: LongWritable, v: Text, collect: ArrayBuffer[(String, Int)]) = {
      for (word <- v.toString.split("\\s+"))
        collect += ((word, 1))
    }
    def reduce(key: String, value: Iterator[Int], collect: ArrayBuffer[(String, Int)]) = {
      collect += ((key, value.sum))
    }
    val rdd = sc.hadoopFile("/hdfs/wordcount/in1/*", classOf[TextInputFormat], classOf[LongWritable], classOf[Text], 2)
      .asInstanceOf[HadoopRDD[LongWritable, Text]]
      .mapPartitionsWithInputSplit((split, it) =>{
        val collect: ArrayBuffer[(String, Int)] = ArrayBuffer[(String, Int)]()
        it.foreach(kv => map(kv._1, kv._2, collect))
        collect.toIterator
      })
      .repartitionAndSortWithinPartitions(new HashPartitioner(2))
      .mapPartitions(it => {
        val collect: ArrayBuffer[(String, Int)] = ArrayBuffer[(String, Int)]()
        var lastKey: String = ""
        var values: ArrayBuffer[Int] = ArrayBuffer[Int]()
        for ((currKey, value) <- it) {
          if (!currKey.equals(lastKey)) {
            if (values.length != 0)
              reduce(lastKey, values.toIterator, collect)
            values.clear()
          }
          values += value
          lastKey = currKey
        }
        if (values.length != 0) reduce(lastKey, values.toIterator, collect)
        collect.toIterator
      })
    rdd.foreach(println)
  }
}

from pyspark.sql.types import StructType, LongType

schema = data.schema.add(StructField("id", LongType()))
rowRDD = data.rdd.zipWithUniqueId().map(lambda t: t[0]+Row(t[1]))
data = rowRDD.toDF(schema)
data.show()

rdd.persist()

sc.setCheckpointDir("checkpoint")
rdd.cache()
rdd.checkpoint()

from graphframes import GraphFrame
vertices = spark.createDataFrame([
    ("a", "Alice", 34),
    ("b", "Bob", 36),
    ("c", "Charlie", 30),
    ("d", "David", 29),
    ("e", "Esther", 32),
    ("f", "Fanny", 36),
    ("g", "Gabby", 60)], ["id", "name", "age"])
edges = spark.createDataFrame([
    ("a", "b", "friend"),
    ("b", "c", "follow"),
    ("c", "b", "follow"),
    ("f", "c", "follow"),
    ("e", "f", "follow"),
    ("e", "d", "friend"),
    ("d", "a", "friend"),
    ("a", "e", "friend")
], ["src", "dst", "relationship"])
# 生成圖
g = GraphFrame(vertices, edges)

print("頂點表視圖：")
graph.vertices.show() # graph.vertices 就是原始的vertices
print("邊表視圖：")
graph.edges.show() # graph.edges 就是原始的 edges
print("三元組視圖：")
graph.triplets.show()

# 頂點的度
graph.degrees.show()
# 頂點的入度
graph.inDegrees.show()
# 頂點的出度
graph.outDegrees.show()

# 多個路徑條件
motif = graph.find("(a)-[e]->(b); (b)-[e2]->(a)")
# 在搜索的結(jié)果上進行過濾
motif.filter("b.age > 30")
# 不需要返回路徑中的元素時，可以使用匿名頂點和邊
motif = graph.find("(start)-[]->()")
# 設(shè)置路徑不存在的條件
motif = graph.find("(a)-[]->(b); !(b)-[]->(a)")

# Motif: A->B->C but not A->C
results = graph.find("(A)-[]->(B); (B)-[]->(C); !(A)-[]->(C)")
# 排除自己
results = results.filter("A.id != C.id")
# 選擇需要的列
results = results.select(results.A.id.alias("A"), results.C.id.alias("C"))
results.show()

from pyspark.sql.functions import col, lit, when
from functools import reduce
chain4 = graph.find("(a)-[ab]->(b); (b)-[bc]->(c); (c)-[cd]->(d)")
def sumFriends(cnt, relationship):
    "定義下一個頂點更新狀態(tài)的條件：如果關(guān)系為friend則cnt+1"
    return when(relationship == "friend", cnt+1).otherwise(cnt)
# 將更新方法應(yīng)用到整個鏈的，鏈上每有一個關(guān)系是 friend 就加一，鏈上共三個關(guān)系。
condition = reduce(lambda cnt, e: sumFriends(
    cnt, col(e).relationship), ["ab", "bc", "cd"], lit(0))
chainWith2Friends2 = chain4.where(condition >= 3)
chainWith2Friends2.show()

graph.filterVertices("age > 30").filterEdges("relationship = 'friend'").dropIsolatedVertices()

paths = graph.find("(a)-[e]->(b)")\
    .filter("e.relationship = 'follow'")\
    .filter("a.age < b.age")
# 抽取邊信息e2 = paths.select("e.src", "e.dst", "e.relationship")
e2 = paths.select("e.*")
# 創(chuàng)建Subgraphs
g2 = GraphFrame(graph.vertices, e2)

results = graph.pageRank(resetProbability=0.15, maxIter=10)
results.vertices.sort("pagerank", ascending=False).show()

graph.pageRank(resetProbability=0.15, maxIter=10, sourceId="a")
graph.parallelPersonalizedPageRank(resetProbability=0.15, sourceIds=["a", "b", "c", "d"], maxIter=10)

paths = graph.bfs("name = 'Esther'", "age < 32")
paths.show()

+--------------+--------------+---------------+
|          from|            e0|             to|
+--------------+--------------+---------------+
|{a, Alice, 34}|{a, e, friend}|{e, Esther, 32}|
+--------------+--------------+---------------+

graph.bfs("name = 'Esther'",
          "age < 32",
          edgeFilter="relationship != 'friend'",
          maxPathLength=4
          ).show()

+---------------+--------------+--------------+--------------+----------------+
|           from|            e0|            v1|            e1|              to|
+---------------+--------------+--------------+--------------+----------------+
|{e, Esther, 32}|{e, f, follow}|{f, Fanny, 36}|{f, c, follow}|{c, Charlie, 30}|
+---------------+--------------+--------------+--------------+----------------+

sc.setCheckpointDir("checkpoint")

graph.connectedComponents().show()

graph.dropIsolatedVertices().connectedComponents().show()

graph.stronglyConnectedComponents(maxIter=10).show()

graph.shortestPaths(landmarks=["a", "d"]).show()

+---+-------+---+----------------+
| id|   name|age|       distances|
+---+-------+---+----------------+
|  g|  Gabby| 60|              {}|
|  f|  Fanny| 36|              {}|
|  e| Esther| 32|{a -> 2, d -> 1}|
|  d|  David| 29|{a -> 1, d -> 0}|
|  c|Charlie| 30|              {}|
|  b|    Bob| 36|              {}|
|  a|  Alice| 34|{a -> 0, d -> 2}|
+---+-------+---+----------------+

graph.triangleCount().show()

+-----+---+-------+---+
|count| id|   name|age|
+-----+---+-------+---+
|    1|  a|  Alice| 34|
|    0|  b|    Bob| 36|
|    0|  c|Charlie| 30|
|    1|  d|  David| 29|
|    1|  e| Esther| 32|
|    0|  g|  Gabby| 60|
|    0|  f|  Fanny| 36|
+-----+---+-------+---+

graph.labelPropagation(maxIter=5).orderBy("label").show()

+---+-------+---+-------------+
| id|   name|age|        label|
+---+-------+---+-------------+
|  g|  Gabby| 60| 146028888064|
|  f|  Fanny| 36|1047972020224|
|  b|    Bob| 36|1047972020224|
|  a|  Alice| 34|1382979469312|
|  c|Charlie| 30|1382979469312|
|  e| Esther| 32|1460288880640|
|  d|  David| 29|1460288880640|
+---+-------+---+-------------+

spark.conf.set("spark.sql.execution.arrow.pyspark.enabled", "true")

df = spark.createDataFrame(
    [(1, 1.0), (1, 2.0), (2, 3.0), (2, 5.0), (2, 10.0)],
    ("id", "v"))
df.show()

from pyspark.sql.functions import pandas_udf
import pandas as pd

@pandas_udf("double")
def multiply_func(a: pd.Series, b: pd.Series) -> pd.Series:
    return a * b
df.select(multiply_func("id", "v").alias("product")).show()

df.createOrReplaceTempView("t")
spark.udf.register("multiply", multiply_func)
spark.sql('select multiply(id, v) product from t').show()

from pyspark.sql import Window

@pandas_udf("double")
def mean_udf(v: pd.Series) -> float:
    return v.mean()
# 對字段'v'進行求均值
df.select(mean_udf('v').alias("mean_v")).show()
# 按照‘id'分組，求'v'的均值
df.groupby("id").agg(mean_udf('v').alias("mean_v")).show()
# 按照‘id'分組，求'v'的均值，并賦值給新的一列
df.withColumn('mean_v', mean_udf("v").over(Window.partitionBy('id'))).show()

spark.udf.register("mean2", mean_udf)
spark.sql('select mean2(v) mean_v from t').show()
spark.sql('select id,mean2(v) mean_v from t group by id').show()
spark.sql('select id,v,mean2(v) over(partition by id) mean_v from t').show()

def subtract_mean(pdf):
    v = pdf.v
    pdf['v1'] = v - v.mean()
    pdf['v2'] = v + v.mean()
    return pdf
t = df.groupby("id")
t.applyInPandas(
    subtract_mean, schema="id long, v double, v1 double, v2 double").show()

val a = sc.parallelize(List(1, 2, 1, 3))
val b = a.map((_, "b"))
val c = a.map((_, "c"))
val d = a.map((_, "d"))
val e = a.map((_, "e"))
scala> b.cogroup(c).foreach(println)
(3,(CompactBuffer(b),CompactBuffer(c)))
(1,(CompactBuffer(b, b),CompactBuffer(c, c)))
(2,(CompactBuffer(b),CompactBuffer(c)))

df1 = spark.createDataFrame(
    [(20000101, 1, 1.0), (20000101, 2, 2.0), (20000102, 1, 3.0), (20000102, 2, 4.0)],
    ("time", "id", "v1"))

df2 = spark.createDataFrame(
    [(20000101, 1, "x"), (20000101, 2, "y")],
    ("time", "id", "v2"))

def asof_join(l, r):
  	# l、r is a pandas.DataFrame
  	# 這里是按照id分組
  	# 那么，l和r分別是對應(yīng)id的df1和df2數(shù)據(jù)
    return pd.merge_asof(l, r, on="time", by="id")

df1.groupby("id").cogroup(df2.groupby("id")).applyInPandas(
    asof_join, schema="time int, id int, v1 double, v2 string").show()
# +--------+---+---+---+
# |    time| id| v1| v2|
# +--------+---+---+---+
# |20000101|  1|1.0|  x|
# |20000102|  1|3.0|  x|
# |20000101|  2|2.0|  y|
# |20000102|  2|4.0|  y|
# +--------+---+---+---+

def filter_func(iterator):
    for i, pdf in enumerate(iterator):
        print(i, pdf.values.tolist())
        yield pdf


df.mapInPandas(filter_func, schema=df.schema).show()

sdf.toPandas()

spark.createDataFrame(pdf)

import os
os.environ["PYARROW_IGNORE_TIMEZONE"] = "1"

df = spark.createDataFrame(
    [(1, 1.0), (1, 2.0), (2, 3.0), (2, 5.0), (2, 10.0)],
    ("id", "v"))

pdf = df.to_pandas_on_spark()
print(type(pdf))
pdf

pdf.to_spark()

import pyspark.pandas as ps

pdf = ps.read_csv("example_csv.csv")

ps.sql("SELECT count(*) as num FROM {pdf}")