我有以下代码：

output = (assignations
          .join(activations,['customer_id','external_id'],'left')
          .join(redeemers,['customer_id','external_id'],'left')
          .groupby('external_id')
          .agg(f.expr('COUNT(DISTINCT(CASE WHEN assignation = 1 THEN customer_id ELSE NULL END))').alias('assigned'),
           f.expr('COUNT(DISTINCT(CASE WHEN activation = 1 THEN customer_id ELSE NULL END))').alias('activated'),
           f.expr('COUNT(DISTINCT(CASE WHEN redeemer = 1 THEN customer_id ELSE NULL END))').alias('redeemed'))
         )

此代码提供以下输出：

external_id          assigned     activated    redeemed
DISC0000089309         31968         901         491
DISC0000089428         31719         893         514
DISC0000089283         2617           60          39

我的想法是改变 case when 部分转换为更具pythonic/pyspark特性的代码。因此我尝试了以下代码：

output = (assignations
          .join(activations,['customer_id','external_id'],'left')
          .join(redeemers,['customer_id','external_id'],'left')
          .groupby('external_id')
          .agg(f.count(f.when(f.col('assignation')==1,True).alias('assigned')),
           f.count(f.when(f.col('activation')==1,True).alias('activated')),
           f.count(f.when(f.col('redeemer')==1,True).alias('redeem'))
         ))

问题是输出不一样，数字不匹配。如何转换代码以获得相同的输出？