Python PySpark：当具有多个输出时
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PySpark: when function with multiple outputs
提问by Fede
I am trying to use a "chained when" function. In other words, I'd like to get more than two outputs.
我正在尝试使用“链接时间”功能。换句话说，我想获得两个以上的输出。
I tried using the same logic of the concatenate IF function in Excel:
我尝试在 Excel 中使用与 concatenate IF 函数相同的逻辑：
df.withColumn("device_id", when(col("device")=="desktop",1)).otherwise(when(col("device")=="mobile",2)).otherwise(null))
But that doesn't work since I can't put a tuple into the "otherwise" function.
但这不起作用，因为我无法将元组放入“otherwise”函数中。
回答by Grr
Have you tried:
你有没有尝试过：
from pyspark.sql import functions as F
df.withColumn('device_id', F.when(col('device')=='desktop', 1).when(col('device')=='mobile', 2).otherwise(None))
Note that when chaining whenfunctions you do not need to wrap the successive calls in an otherwisefunction.
请注意，当链接when函数时，您不需要将连续调用包装在一个otherwise函数中。
