如何根据同一列的条件更改 PySpark 数据帧中的值

Question

考虑一个示例数据帧：

df = 
+-------+-----+
|   tech|state|
+-------+-----+
|     70|wa   |
|     50|mn   |
|     20|fl   |
|     50|mo   |
|     10|ar   |
|     90|wi   |
|     30|al   |
|     50|ca   |
+-------+-----+

我想更改"tech"列，以便将 50 的任何值更改为 1，所有其他值都等于 0。

输出如下所示：

df = 
+-------+-----+
|   tech|state|
+-------+-----+
|     0 |wa   |
|     1 |mn   |
|     0 |fl   |
|     1 |mo   |
|     0 |ar   |
|     0 |wi   |
|     0 |al   |
|     1 |ca   |
+-------+-----+

这是我到目前为止所拥有的：

from pyspark.sql.functions import UserDefinedFunction
from pyspark.sql.types import StringType

changing_column = 'tech'
udf_first = UserDefinedFunction(lambda x: 1, IntegerType())
udf_second = UserDefinedFunction(lambda x: 0, IntegerType())
first_df = zero_df.select(*[udf_first(changing_column) if column == 50 else column for column in zero_df])
second_df = first_df.select(*[udf_second(changing_column) if column != 50 else column for column in first_df])
second_df.show()

Answer 1

希望这有帮助

from pyspark.sql.functions import when
df = spark
.createDataFrame([
    (70, 'wa'),
    (50, 'mn'),
    (20, 'fl')],
    ["tech", "state"])
df
.select("*", when(df.tech == 50, 1)
        .otherwise(0)
        .alias("tech"))
.show()
+----+-----+----+
|tech|state|tech|
+----+-----+----+
|  70|   wa|   0|
|  50|   mn|   1|
|  20|   fl|   0|
+----+-----+----+