如何从pyspark dataframe中的datetime中提取小时？

from pyspark.sql import SparkSession
from pyspark.sql.functions import hour

spark = SparkSession.builder.getOrCreate()

data = [("2021-01-01 10:15:30"), ("2021-01-02 12:30:45"), ("2021-01-03 15:45:00")]
df = spark.createDataFrame(data, ["datetime"])

df_with_hour = df.withColumn("hour", hour(df.datetime))

df_with_hour.show()

+-------------------+----+
|           datetime|hour|
+-------------------+----+
|2021-01-01 10:15:30|  10|
|2021-01-02 12:30:45|  12|
|2021-01-03 15:45:00|  15|
+-------------------+----+