将PySpark数据框中的一行拆分为多行 [英] Splitting a row in a PySpark Dataframe into multiple rows

问题描述

我目前有一个数据帧，其中一列的类型为"a b c d e ...".将此列称为"col4"

我想通过拆分col4的元素将一行拆分为多个，并保留所有其他列的值.

例如，给定一个具有单行的df:

col1 [0] | col2 [0] | col3 [0] | a b c |

我希望输出为:

col1 [0] | col2 [0] | col3 [0] |一个|

col1 [0] | col2 [0] | col3 [0] | b |

col1 [0] | col2 [0] | col3 [0] | c |

使用split和explode函数，我尝试了以下操作:

d = COMBINED_DF.select(col1, col2, col3, explode(split(my_fun(col4), " ")))

但是，这将导致以下输出:

col1 [0] | col2 [0] | col3 [0] | a b c |

col1 [0] | col2 [0] | col3 [0] | a b c |

col1 [0] | col2 [0] | col3 [0] | a b c |

这不是我想要的.

解决方案

以下是可重现的示例:

# Create dummy data
df = sc.parallelize([(1, 2, 3, 'a b c'),
                     (4, 5, 6, 'd e f'),
                     (7, 8, 9, 'g h i')]).toDF(['col1', 'col2', 'col3','col4'])


# Explode column
from pyspark.sql.functions import split, explode
df.withColumn('col4',explode(split('col4',' '))).show()
+----+----+----+----+
|col1|col2|col3|col4|
+----+----+----+----+
|   1|   2|   3|   a|
|   1|   2|   3|   b|
|   1|   2|   3|   c|
|   4|   5|   6|   d|
|   4|   5|   6|   e|
|   4|   5|   6|   f|
|   7|   8|   9|   g|
|   7|   8|   9|   h|
|   7|   8|   9|   i|
+----+----+----+----+

I currently have a dataframe where one column is of type "a b c d e ...". Call this column "col4"

I would like to split a single row into multiple by splitting the elements of col4, preserving the value of all the other columns.

So, for example, given a df with single row:

col1[0] | col2[0] | col3[0] | a b c |

I would like the output to be:

col1[0] | col2[0] | col3[0] | a |

col1[0] | col2[0] | col3[0] | b |

col1[0] | col2[0] | col3[0] | c |

Using the split and explode functions, I have tried the following:

d = COMBINED_DF.select(col1, col2, col3, explode(split(my_fun(col4), " ")))

However, this results in the following output:

col1[0] | col2[0] | col3[0] | a b c |

col1[0] | col2[0] | col3[0] | a b c |

col1[0] | col2[0] | col3[0] | a b c |

which is not what I want.

解决方案

Here's a reproducible example:

# Create dummy data
df = sc.parallelize([(1, 2, 3, 'a b c'),
                     (4, 5, 6, 'd e f'),
                     (7, 8, 9, 'g h i')]).toDF(['col1', 'col2', 'col3','col4'])


# Explode column
from pyspark.sql.functions import split, explode
df.withColumn('col4',explode(split('col4',' '))).show()
+----+----+----+----+
|col1|col2|col3|col4|
+----+----+----+----+
|   1|   2|   3|   a|
|   1|   2|   3|   b|
|   1|   2|   3|   c|
|   4|   5|   6|   d|
|   4|   5|   6|   e|
|   4|   5|   6|   f|
|   7|   8|   9|   g|
|   7|   8|   9|   h|
|   7|   8|   9|   i|
+----+----+----+----+

这篇关于将PySpark数据框中的一行拆分为多行的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！