你可以数数 Score Windows上方 ID ，然后打开过滤器 Score 不为null或计数为0：

from pyspark.sql import Window
from pyspark.sql import functions as F

df1 = df.withColumn(
    "count_scores",
    F.count("Score").over(Window.partitionBy("ID"))
).where("Score IS NOT NULL OR count_scores = 0")\
 .drop("count_scores")

df1.show()

# +---+-----+

# | ID|Score|

# +---+-----+

# |BBB| null|

# |AAA| High|

# |AAA|  Mid|

# +---+-----+

您可以添加是否所有分数都为空的标志，并过滤分数不为空或标志为真（所有分数都为空）时的行：

from pyspark.sql import functions as F, Window

df2 = df.withColumn(
    'flag', 
    F.min(F.col('Score').isNull()).over(Window.partitionBy('ID'))
).filter('flag or Score is not null').drop('flag')

df2.show()
+---+-----+
| ID|Score|
+---+-----+
|BBB| null|
|AAA| High|
|AAA|  Mid|
+---+-----+