Filtering a pyspark dataframe using isin by exclusion [duplicate]

可紊 提交于 2020-04-27 19:46:51

问题


I am trying to get all rows within a dataframe where a columns value is not within a list (so filtering by exclusion).

As an example:

df = sqlContext.createDataFrame([('1','a'),('2','b'),('3','b'),('4','c'),('5','d')]
,schema=('id','bar'))

I get the data frame:

+---+---+
| id|bar|
+---+---+
|  1|  a|
|  2|  b|
|  3|  b|
|  4|  c|
|  5|  d|
+---+---+

I only want to exclude rows where bar is ('a' or 'b').

Using an SQL expression string it would be:

df.filter('bar not in ("a","b")').show()

Is there a way of doing it without using the string for the SQL expression, or excluding one item at a time?

Edit:

I am likely to have a list, ['a','b'], of the excluded values that I would like to use.


回答1:


It looks like the ~ gives the functionality that I need, but I am yet to find any appropriate documentation on it.

df.filter(~col('bar').isin(['a','b'])).show()



+---+---+
| id|bar|
+---+---+
|  4|  c|
|  5|  d|
+---+---+



回答2:


Also could be like this

df.filter(col('bar').isin(['a','b']) == False).show()



回答3:


Got a gotcha for those with their headspace in Pandas and moving to pyspark

 from pyspark import SparkConf, SparkContext
 from pyspark.sql import SQLContext

 spark_conf = SparkConf().setMaster("local").setAppName("MyAppName")
 sc = SparkContext(conf = spark_conf)
 sqlContext = SQLContext(sc)

 records = [
     {"colour": "red"},
     {"colour": "blue"},
     {"colour": None},
 ]

 pandas_df = pd.DataFrame.from_dict(records)
 pyspark_df = sqlContext.createDataFrame(records)

So if we wanted the rows that are not red:

pandas_df[~pandas_df["colour"].isin(["red"])]

Looking good, and in our pyspark DataFrame

pyspark_df.filter(~pyspark_df["colour"].isin(["red"])).collect()

So after some digging, I found this: https://issues.apache.org/jira/browse/SPARK-20617 So to include nothingness in our results:

pyspark_df.filter(~pyspark_df["colour"].isin(["red"]) | pyspark_df["colour"].isNull()).show()




回答4:


df.filter((df.bar != 'a') & (df.bar != 'b'))


来源:https://stackoverflow.com/questions/41775281/filtering-a-pyspark-dataframe-using-isin-by-exclusion

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