如果表未分区，上述代码将失败。它会给你一个错误信息，如 "pyspark.sql.utils.AnalysisException: u'SHOW PARTITIONS is not allowed on a table that is not partitioned" 您可以在上使用Map操作 desc 命令获取分区列信息。

>>> spark.sql("""desc db.newpartitiontable""").show(truncate=False)
+-----------------------+---------+-------+
|col_name               |data_type|comment|
+-----------------------+---------+-------+
|city                   |string   |null   |
|state                  |string   |null   |
|country                |string   |null   |
|tran_date              |string   |null   |
|# Partition Information|         |       |
|# col_name             |data_type|comment|
|tran_date              |string   |null   |
+-----------------------+---------+-------+
partition_exists=spark.sql("""desc db.newpartitiontable""").rdd.map(lambda x:x[0]).filter(lambda x: x.startswith("# col_name")).collect()
if len(partition_exists)>0:
    print("table is partitioned")
    partition_col=spark.sql("""show partitions test_dev_db.newpartitiontable""").rdd.map(lambda x:x[0]).map(lambda x : [l.split('=')[0] for l in x.split('/')]).first()
    print("Partition column is:",partition_col)
else:
    print("table is not partitioned")