Spark.sql : Remove table's name on columns name - python

when I query my database as :
spark.sql("SELECT * FROM MyBase")
I have "MyBase." in front of all my column's name.
Can we simply avoid that ? If not, what is the best way to remove it ?
Example :
df = spark.sql("SELECT name, price FROM MyBase")
df.show(2)
+-------------+--------------+
| mybase.name | mybase.price |
+-------------+--------------+
| Jean | 15.0 |
| Phil | 10.0 |
+-------------+--------------+
I just want name and price as column name.
Thanks

It seems that you set the option
hive.resultset.use.unique.column.names=true
for somewhere in your hive-site.xml or on the spark session. It should be false for your purpose.

Try providing new set of columns to your dataframe by removing the prefix name upto .. Here is a sample solution which will work for all columns.
data = [(1,2,3), (11,22,33)]
df1 = spark.createDataFrame(data,['a.a','a.b','a.c'])
df1.show()
"""
+---+---+---+
|a.a|a.b|a.c|
+---+---+---+
| 1| 2| 3|
| 11| 22| 33|
+---+---+---+
"""
new_cols = [i[i.find('.')+1:] for i in df1.columns]
df2 = df1.toDF(*new_cols)
df2.show()
"""
+---+---+---+
| a| b| c|
+---+---+---+
| 1| 2| 3|
| 11| 22| 33|
+---+---+---+
"""

data = [(1,2,3), (11,22,33)]
df1 = spark.createDataFrame(data,['a.a','a.b','a.c'])
cols = [x.split('.')[1] for x in df1.columns]
display(df1.toDF(*cols))

Related

Is there a way to add a column with range of values to a Spark Dataframe?

I have a spark dataframe: df1 as below:
age = spark.createDataFrame(["10","11","13"], "string").toDF("age")
age.show()
+---+
|age|
+---+
| 10|
| 11|
| 13|
+---+
I have a requirement of adding a row number column to the dataframe to make it:
+---+------+
|age|col_id|
+---+------+
| 10| 1 |
| 11| 2 |
| 13| 3 |
+---+------+
None of the columns in my dataframe contains unique values.
I tried to use F.monotonically_increasing_id()) but it is just producing random numbers in increasing order.
>>> age = spark.createDataFrame(["10","11","13"], "string").toDF("age").withColumn("rowId1", F.monotonically_increasing_id())
>>> age
DataFrame[age: string, rowId1: bigint]
>>> age.show
<bound method DataFrame.show of DataFrame[age: string, rowId1: bigint]>
>>> age.show()
+---+-----------+
|age| rowId1|
+---+-----------+
| 10|17179869184|
| 11|42949672960|
| 13|60129542144|
+---+-----------+
Since I don't have any column with unique data, I am worried about using windowing functions and generate row_numbers.
So, is there a way I can add a column with row_count to the dataframe that gives:
+---+------+
|age|col_id|
+---+------+
| 10| 1 |
| 11| 2 |
| 13| 3 |
+---+------+
If windowing function is the only way to implement, how can I make sure all the data comes under a single partition ?
or if there is a way to implement the same without using windowing functions, how to implement it ?
Any help is appreciated.
Use zipWithIndex.
I could not find code I did myself in the past yesterday as I was busy working on issues, but here is a good post that explains it. https://sqlandhadoop.com/pyspark-zipwithindex-example/
pyspark different to Scala.
Other answer not good for performance - going to single Executor. zipWithIndex is narrow transformation so it works per partition.
Here goes, you can tailor accordingly:
from pyspark.sql.types import StructField
from pyspark.sql.types import StructType
from pyspark.sql.types import StringType, LongType
import pyspark.sql.functions as F
df1 = spark.createDataFrame([ ('abc'),('2'),('3'),('4'), ('abc'),('2'),('3'),('4'), ('abc'),('2'),('3'),('4') ], StringType())
schema = StructType(df1.schema.fields[:] + [StructField("index", LongType(), True)])
rdd = df1.rdd.zipWithIndex()
rdd1 = rdd.map(lambda row: tuple(row[0].asDict()[c] for c in schema.fieldNames()[:-1]) + (row[1],))
df1 = spark.createDataFrame(rdd1, schema)
df1.show()
returns:
+-----+-----+
|value|index|
+-----+-----+
| abc| 0|
| 2| 1|
| 3| 2|
| 4| 3|
| abc| 4|
| 2| 5|
| 3| 6|
| 4| 7|
| abc| 8|
| 2| 9|
| 3| 10|
| 4| 11|
+-----+-----+
Assumption: This answer is based on the assumption that the order of col_id should depend on the age column. If the assumption does not hold true the other suggested solution is the in the questions comments mentioned zipWithIndex. An example usage of zipWithIndex can be found in this answer.
Proposed solution:
You can use a window with an empty partitionBy and the the row number to get the expected numbers.
from pyspark.sql.window import Window
from pyspark.sql import functions as F
windowSpec = Window.partitionBy().orderBy(F.col('age').asc())
age = age.withColumn(
'col_id',
F.row_number().over(windowSpec)
)
[EDIT] Add assumption of requirements and reference to alternative solution.

Pyspark pivot on multiple column names

I currently have a dataframe df
id | c1 | c2 | c3 |
1 | diff | same | diff
2 | same | same | same
3 | diff | same | same
4 | same | same | same
I want my output to look like
name| diff | same
c1 | 2 | 2
c2 | 0 | 4
c3 | 1 | 3
When I try :
df.groupby('c2').pivot('c2').count() -> transformation A
|f2 | diff | same |
|same | null | 2
|diff | 2 | null
I'm assuming I need to write a loop for each column and pass it through transformation A?
But I'm having issues getting transformation A right.
Please help
Pivot is an expensive shuffle operation and should be avoided if possible. Try using this logic with arrays_zip and explode to dynamically collapse columns and groupby-aggregate.
from pyspark.sql import functions as F
df.withColumn("cols", F.explode(F.arrays_zip(F.array([F.array(F.col(x),F.lit(x))\
for x in df.columns if x!='id']))))\
.withColumn("name", F.col("cols.0")[1]).withColumn("val", F.col("cols.0")[0]).drop("cols")\
.groupBy("name").agg(F.count(F.when(F.col("val")=='diff',1)).alias("diff"),\
F.count(F.when(F.col("val")=='same',1)).alias("same")).orderBy("name").show()
#+----+----+----+
#|name|diff|same|
#+----+----+----+
#| c1| 2| 2|
#| c2| 0| 4|
#| c3| 1| 3|
#+----+----+----+
You can also do this by exploding a map_type by creating a map dynamically.
from pyspark.sql import functions as F
from itertools import chain
df.withColumn("cols", F.create_map(*(chain(*[(F.lit(name), F.col(name))\
for name in df.columns if name!='id']))))\
.select(F.explode("cols").alias("name","val"))\
.groupBy("name").agg(F.count(F.when(F.col("val")=='diff',1)).alias("diff"),\
F.count(F.when(F.col("val")=='same',1)).alias("same")).orderBy("name").show()
#+----+----+----+
#|name|diff|same|
#+----+----+----+
#| c1| 2| 2|
#| c2| 0| 4|
#| c3| 1| 3|
#+----+----+----+
from pyspark.sql.functions import *
df = spark.createDataFrame([(1,'diff','same','diff'),(2,'same','same','same'),(3,'diff','same','same'),(4,'same','same','same')],['idcol','C1','C2','C3'])
df.createOrReplaceTempView("MyTable")
#spark.sql("select * from MyTable").collect()
x1=spark.sql("select idcol, 'C1' AS col, C1 from MyTable union all select idcol, 'C2' AS col, C2 from MyTable union all select idcol, 'C3' AS col, C3 from MyTable")
#display(x1)
x2=x1.groupBy('col').pivot('C1').agg(count('C1')).orderBy('col')
display(x2)

How to merge two dataframe in pyspark when one column is an array and another column is string?

df1:
+---+------+
| id| code|
+---+------+
| 1|[A, F]|
| 2| [G]|
| 3| [A]|
+---+------+
df2:
+--------+----+
| col1|col2|
+--------+----+
| Apple| A|
| Google| G|
|Facebook| F|
+--------+----+
I want the df3 should be like this by using the df1, and df2 columns :
+---+------+-----------------+
| id| code| changed|
+---+------+-----------------+
| 1|[A, F]|[Apple, Facebook]|
| 2| [G]| [Google]|
| 3| [A]| [Apple]|
+---+------+-----------------+
I know this can be archived if the code column is NOT an ARRAY. I don't know how to iterate the code array for this purpose.
Try:
from pyspark.sql.functions import *
import pyspark.sql.functions as f
res=(df1
.select(f.col("id"), f.explode(f.col("code")).alias("code"))
.join(df2, f.col("code")==df2.col2)
.groupBy("id")
.agg(f.collect_list(f.col("code")).alias("code"), f.collect_list(f.col("col1")).alias("changed"))
)

Looking to convert String Column to Integer Column in PySpark. What happens to strings that can't be converted?

I'm trying to convert a column in a dataframe to IntegerType. Here is an example of the dataframe:
+----+-------+
|From| To|
+----+-------+
| 1|1664968|
| 2| 3|
| 2| 747213|
| 2|1664968|
| 2|1691047|
| 2|4095634|
+----+-------+
I'm using the following code:
exploded_df = exploded_df.withColumn('From', exploded_df['To'].cast(IntegerType()))
However, I wanted to know what happens to strings that are not digits, for example, what happens if I have a string with several spaces? The reason is that I want to filter the dataframe in order to get the values of the column 'From' that don't have numbers in column 'To'.
Is there a simpler way to filter by this condition without converting the columns to IntegerType?
Thank you!
Values which cannot be cast are set to null, and the column will be considered a nullable column of that type. Here's a simple example:
from pyspark import SQLContext
from pyspark.sql import SparkSession
import pyspark.sql.functions as F
from pyspark.sql.types import IntegerType
spark = SparkSession.builder.getOrCreate()
sql_context = SQLContext(spark.sparkContext)
df = sql_context.createDataFrame([("1",),
("2",),
("3",),
("4",),
("hello world",)], schema=['id'])
print(df.show())
df = df.withColumn("id", F.col("id").astype(IntegerType()))
print(df.show())
Output:
+-----------+
| id|
+-----------+
| 1|
| 2|
| 3|
| 4|
|hello world|
+-----------+
+----+
| id|
+----+
| 1|
| 2|
| 3|
| 4|
|null|
+----+
And to verify the schema is correct:
print(df.printSchema())
Output:
None
root
|-- id: integer (nullable = true)
Hope this helps!
We can use regex to check does To column have some alphabets,spaces in the data, Using .rlike funtion in spark to filter out the matching rows.
Example:
df=spark.createDataFrame([("1","1664968"),("2","3"),("2","742a7"),("2"," "),("2","a")],["From","To"])
df.show()
#+----+-------+
#|From| To|
#+----+-------+
#| 1|1664968|
#| 2| 3|
#| 2| 742a7|
#| 2| |
#| 2| a|
#+----+-------+
#get the rows which have space or word in them
df.filter(col("To").rlike('([a-z]|\\s+)')).show(truncate=False)
#+----+-----+
#|From|To |
#+----+-----+
#|2 |742a7|
#|2 | |
#|2 |a |
#+----+-----+
#to get rows which doesn't have any space or word in them.
df.filter(~col("To").rlike('([a-z]|\\s+)')).show(truncate=False)
#+----+-------+
#|From|To |
#+----+-------+
#|1 |1664968|
#|2 |3 |
#+----+-------+

Concatenate two PySpark dataframes

I'm trying to concatenate two PySpark dataframes with some columns that are only on one of them:
from pyspark.sql.functions import randn, rand
df_1 = sqlContext.range(0, 10)
+--+
|id|
+--+
| 0|
| 1|
| 2|
| 3|
| 4|
| 5|
| 6|
| 7|
| 8|
| 9|
+--+
df_2 = sqlContext.range(11, 20)
+--+
|id|
+--+
| 10|
| 11|
| 12|
| 13|
| 14|
| 15|
| 16|
| 17|
| 18|
| 19|
+--+
df_1 = df_1.select("id", rand(seed=10).alias("uniform"), randn(seed=27).alias("normal"))
df_2 = df_2.select("id", rand(seed=10).alias("uniform"), randn(seed=27).alias("normal_2"))
and now I want to generate a third dataframe. I would like something like pandas concat:
df_1.show()
+---+--------------------+--------------------+
| id| uniform| normal|
+---+--------------------+--------------------+
| 0| 0.8122802274304282| 1.2423430583597714|
| 1| 0.8642043127063618| 0.3900018344856156|
| 2| 0.8292577771850476| 1.8077401259195247|
| 3| 0.198558705368724| -0.4270585782850261|
| 4|0.012661361966674889| 0.702634599720141|
| 5| 0.8535692890157796|-0.42355804115129153|
| 6| 0.3723296190171911| 1.3789648582622995|
| 7| 0.9529794127670571| 0.16238718777444605|
| 8| 0.9746632635918108| 0.02448061333761742|
| 9| 0.513622008243935| 0.7626741803250845|
+---+--------------------+--------------------+
df_2.show()
+---+--------------------+--------------------+
| id| uniform| normal_2|
+---+--------------------+--------------------+
| 11| 0.3221262660507942| 1.0269298899109824|
| 12| 0.4030672316912547| 1.285648175568798|
| 13| 0.9690555459609131|-0.22986601831364423|
| 14|0.011913836266515876| -0.678915153834693|
| 15| 0.9359607054250594|-0.16557488664743034|
| 16| 0.45680471157575453| -0.3885563551710555|
| 17| 0.6411908952297819| 0.9161177183227823|
| 18| 0.5669232696934479| 0.7270125277020573|
| 19| 0.513622008243935| 0.7626741803250845|
+---+--------------------+--------------------+
#do some concatenation here, how?
df_concat.show()
| id| uniform| normal| normal_2 |
+---+--------------------+--------------------+------------+
| 0| 0.8122802274304282| 1.2423430583597714| None |
| 1| 0.8642043127063618| 0.3900018344856156| None |
| 2| 0.8292577771850476| 1.8077401259195247| None |
| 3| 0.198558705368724| -0.4270585782850261| None |
| 4|0.012661361966674889| 0.702634599720141| None |
| 5| 0.8535692890157796|-0.42355804115129153| None |
| 6| 0.3723296190171911| 1.3789648582622995| None |
| 7| 0.9529794127670571| 0.16238718777444605| None |
| 8| 0.9746632635918108| 0.02448061333761742| None |
| 9| 0.513622008243935| 0.7626741803250845| None |
| 11| 0.3221262660507942| None | 0.123 |
| 12| 0.4030672316912547| None |0.12323 |
| 13| 0.9690555459609131| None |0.123 |
| 14|0.011913836266515876| None |0.18923 |
| 15| 0.9359607054250594| None |0.99123 |
| 16| 0.45680471157575453| None |0.123 |
| 17| 0.6411908952297819| None |1.123 |
| 18| 0.5669232696934479| None |0.10023 |
| 19| 0.513622008243935| None |0.916332123 |
+---+--------------------+--------------------+------------+
Is that possible?
Maybe you can try creating the unexisting columns and calling union (unionAll for Spark 1.6 or lower):
from pyspark.sql.functions import lit
cols = ['id', 'uniform', 'normal', 'normal_2']
df_1_new = df_1.withColumn("normal_2", lit(None)).select(cols)
df_2_new = df_2.withColumn("normal", lit(None)).select(cols)
result = df_1_new.union(df_2_new)
# To remove the duplicates:
result = result.dropDuplicates()
df_concat = df_1.union(df_2)
The dataframes may need to have identical columns, in which case you can use withColumn() to create normal_1 and normal_2
unionByName is a built-in option available in spark which is available from spark 2.3.0.
with spark version 3.1.0, there is allowMissingColumns option with the default value set to False to handle missing columns. Even if both dataframes don't have the same set of columns, this function will work, setting missing column values to null in the resulting dataframe.
df_1.unionByName(df_2, allowMissingColumns=True).show()
+---+--------------------+--------------------+--------------------+
| id| uniform| normal| normal_2|
+---+--------------------+--------------------+--------------------+
| 0| 0.8122802274304282| 1.2423430583597714| null|
| 1| 0.8642043127063618| 0.3900018344856156| null|
| 2| 0.8292577771850476| 1.8077401259195247| null|
| 3| 0.198558705368724| -0.4270585782850261| null|
| 4|0.012661361966674889| 0.702634599720141| null|
| 5| 0.8535692890157796|-0.42355804115129153| null|
| 6| 0.3723296190171911| 1.3789648582622995| null|
| 7| 0.9529794127670571| 0.16238718777444605| null|
| 8| 0.9746632635918108| 0.02448061333761742| null|
| 9| 0.513622008243935| 0.7626741803250845| null|
| 11| 0.3221262660507942| null| 1.0269298899109824|
| 12| 0.4030672316912547| null| 1.285648175568798|
| 13| 0.9690555459609131| null|-0.22986601831364423|
| 14|0.011913836266515876| null| -0.678915153834693|
| 15| 0.9359607054250594| null|-0.16557488664743034|
| 16| 0.45680471157575453| null| -0.3885563551710555|
| 17| 0.6411908952297819| null| 0.9161177183227823|
| 18| 0.5669232696934479| null| 0.7270125277020573|
| 19| 0.513622008243935| null| 0.7626741803250845|
+---+--------------------+--------------------+--------------------+
You can use unionByName to make this:
df = df_1.unionByName(df_2)
unionByName is available since Spark 2.3.0.
To make it more generic of keeping both columns in df1 and df2:
import pyspark.sql.functions as F
# Keep all columns in either df1 or df2
def outter_union(df1, df2):
# Add missing columns to df1
left_df = df1
for column in set(df2.columns) - set(df1.columns):
left_df = left_df.withColumn(column, F.lit(None))
# Add missing columns to df2
right_df = df2
for column in set(df1.columns) - set(df2.columns):
right_df = right_df.withColumn(column, F.lit(None))
# Make sure columns are ordered the same
return left_df.union(right_df.select(left_df.columns))
To concatenate multiple pyspark dataframes into one:
from functools import reduce
reduce(lambda x,y:x.union(y), [df_1,df_2])
And you can replace the list of [df_1, df_2] to a list of any length.
Here is one way to do it, in case it is still useful: I ran this in pyspark shell, Python version 2.7.12 and my Spark install was version 2.0.1.
PS: I guess you meant to use different seeds for the df_1 df_2 and the code below reflects that.
from pyspark.sql.types import FloatType
from pyspark.sql.functions import randn, rand
import pyspark.sql.functions as F
df_1 = sqlContext.range(0, 10)
df_2 = sqlContext.range(11, 20)
df_1 = df_1.select("id", rand(seed=10).alias("uniform"), randn(seed=27).alias("normal"))
df_2 = df_2.select("id", rand(seed=11).alias("uniform"), randn(seed=28).alias("normal_2"))
def get_uniform(df1_uniform, df2_uniform):
if df1_uniform:
return df1_uniform
if df2_uniform:
return df2_uniform
u_get_uniform = F.udf(get_uniform, FloatType())
df_3 = df_1.join(df_2, on = "id", how = 'outer').select("id", u_get_uniform(df_1["uniform"], df_2["uniform"]).alias("uniform"), "normal", "normal_2").orderBy(F.col("id"))
Here are the outputs I get:
df_1.show()
+---+-------------------+--------------------+
| id| uniform| normal|
+---+-------------------+--------------------+
| 0|0.41371264720975787| 0.5888539012978773|
| 1| 0.7311719281896606| 0.8645537008427937|
| 2| 0.1982919638208397| 0.06157382353970104|
| 3|0.12714181165849525| 0.3623040918178586|
| 4| 0.7604318153406678|-0.49575204523675975|
| 5|0.12030715258495939| 1.0854146699817222|
| 6|0.12131363910425985| -0.5284523629183004|
| 7|0.44292918521277047| -0.4798519469521663|
| 8| 0.8898784253886249| -0.8820294772950535|
| 9|0.03650707717266999| -2.1591956435415334|
+---+-------------------+--------------------+
df_2.show()
+---+-------------------+--------------------+
| id| uniform| normal_2|
+---+-------------------+--------------------+
| 11| 0.1982919638208397| 0.06157382353970104|
| 12|0.12714181165849525| 0.3623040918178586|
| 13|0.12030715258495939| 1.0854146699817222|
| 14|0.12131363910425985| -0.5284523629183004|
| 15|0.44292918521277047| -0.4798519469521663|
| 16| 0.8898784253886249| -0.8820294772950535|
| 17| 0.2731073068483362|-0.15116027592854422|
| 18| 0.7784518091224375| -0.3785563841011868|
| 19|0.43776394586845413| 0.47700719174464357|
+---+-------------------+--------------------+
df_3.show()
+---+-----------+--------------------+--------------------+
| id| uniform| normal| normal_2|
+---+-----------+--------------------+--------------------+
| 0| 0.41371265| 0.5888539012978773| null|
| 1| 0.7311719| 0.8645537008427937| null|
| 2| 0.19829196| 0.06157382353970104| null|
| 3| 0.12714182| 0.3623040918178586| null|
| 4| 0.7604318|-0.49575204523675975| null|
| 5|0.120307155| 1.0854146699817222| null|
| 6| 0.12131364| -0.5284523629183004| null|
| 7| 0.44292918| -0.4798519469521663| null|
| 8| 0.88987845| -0.8820294772950535| null|
| 9|0.036507078| -2.1591956435415334| null|
| 11| 0.19829196| null| 0.06157382353970104|
| 12| 0.12714182| null| 0.3623040918178586|
| 13|0.120307155| null| 1.0854146699817222|
| 14| 0.12131364| null| -0.5284523629183004|
| 15| 0.44292918| null| -0.4798519469521663|
| 16| 0.88987845| null| -0.8820294772950535|
| 17| 0.27310732| null|-0.15116027592854422|
| 18| 0.7784518| null| -0.3785563841011868|
| 19| 0.43776396| null| 0.47700719174464357|
+---+-----------+--------------------+--------------------+
Above answers are very elegant. I have written this function long back where i was also struggling to concatenate two dataframe with distinct columns.
Suppose you have dataframe sdf1 and sdf2
from pyspark.sql import functions as F
from pyspark.sql.types import *
def unequal_union_sdf(sdf1, sdf2):
s_df1_schema = set((x.name, x.dataType) for x in sdf1.schema)
s_df2_schema = set((x.name, x.dataType) for x in sdf2.schema)
for i,j in s_df2_schema.difference(s_df1_schema):
sdf1 = sdf1.withColumn(i,F.lit(None).cast(j))
for i,j in s_df1_schema.difference(s_df2_schema):
sdf2 = sdf2.withColumn(i,F.lit(None).cast(j))
common_schema_colnames = sdf1.columns
sdk = \
sdf1.select(common_schema_colnames).union(sdf2.select(common_schema_colnames))
return sdk
sdf_concat = unequal_union_sdf(sdf1, sdf2)
This should do it for you ...
from pyspark.sql.types import FloatType
from pyspark.sql.functions import randn, rand, lit, coalesce, col
import pyspark.sql.functions as F
df_1 = sqlContext.range(0, 6)
df_2 = sqlContext.range(3, 10)
df_1 = df_1.select("id", lit("old").alias("source"))
df_2 = df_2.select("id")
df_1.show()
df_2.show()
df_3 = df_1.alias("df_1").join(df_2.alias("df_2"), df_1.id == df_2.id, "outer")\
.select(\
[coalesce(df_1.id, df_2.id).alias("id")] +\
[col("df_1." + c) for c in df_1.columns if c != "id"])\
.sort("id")
df_3.show()
I was trying to implement pandas append functionality in pyspark and what I created a custom function where we can concat 2 or more data frame even they are having different no. of columns only condition is if dataframes have identical name then their datatype should be same/match.
I have written a custom function to merge 2 dataframes.
def append_dfs(df1,df2):
list1 = df1.columns
list2 = df2.columns
for col in list2:
if(col not in list1):
df1 = df1.withColumn(col, F.lit(None))
for col in list1:
if(col not in list2):
df2 = df2.withColumn(col, F.lit(None))
return df1.unionByName(df2)
usage:
concate 2 dataframes
final_df = append_dfs(df1,df2)
concate more than 2(say3) dataframes
final_df = append_dfs(append_dfs(df1,df2),df3)
example:
df1:
df2:
result=append_dfs(df1,df2)
result :
Hope this will useful.
I would solve this in this way:
from pyspark.sql import SparkSession
df_1.createOrReplaceTempView("tab_1")
df_2.createOrReplaceTempView("tab_2")
df_concat=spark.sql("select tab_1.id,tab_1.uniform,tab_1.normal,tab_2.normal_2 from tab_1 tab_1 left join tab_2 tab_2 on tab_1.uniform=tab_2.uniform\
union\
select tab_2.id,tab_2.uniform,tab_1.normal,tab_2.normal_2 from tab_2 tab_2 left join tab_1 tab_1 on tab_1.uniform=tab_2.uniform")
df_concat.show()
Maybe, you want to concatenate more of two Dataframes.
I found a issue which use pandas Dataframe conversion.
Suppose you have 3 spark Dataframe who want to concatenate.
The code is the following:
list_dfs = []
list_dfs_ = []
df = spark.read.json('path_to_your_jsonfile.json',multiLine = True)
df2 = spark.read.json('path_to_your_jsonfile2.json',multiLine = True)
df3 = spark.read.json('path_to_your_jsonfile3.json',multiLine = True)
list_dfs.extend([df,df2,df3])
for df in list_dfs :
df = df.select([column for column in df.columns]).toPandas()
list_dfs_.append(df)
list_dfs.clear()
df_ = sqlContext.createDataFrame(pd.concat(list_dfs_))

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