我找不到任何解决问题的办法。
如果我试图定义spark udf函数（pyspark），例如：

@udf(returnType=IntegerType())
def _return_an_integer(y):

    return y + random.randint(1, 99)

df = df.withColumn('randomInteger', _return_an_integer(col('1')))

我收到错误消息：

TypeError: udf() missing 1 required positional argument: 'f'

有人能解决这个问题吗？
提前谢谢！
编辑：不带注解：

Py4JError: An error occurred while calling None.org.apache.spark.sql.execution.python.UserDefinedPythonFunction. Trace:
py4j.Py4JException: Constructor org.apache.spark.sql.execution.python.UserDefinedPythonFunction([class java.lang.String, class org.apache.spark.api.python.PythonFunction, class org.apache.spark.sql.types.IntegerType$]) does not exist
    at py4j.reflection.ReflectionEngine.getConstructor(ReflectionEngine.java:179)
    at py4j.reflection.ReflectionEngine.getConstructor(ReflectionEngine.java:196)
    at py4j.Gateway.invoke(Gateway.java:237)
    at py4j.commands.ConstructorCommand.invokeConstructor(ConstructorCommand.java:80)
    at py4j.commands.ConstructorCommand.execute(ConstructorCommand.java:69)
    at py4j.GatewayConnection.run(GatewayConnection.java:238)
    at java.lang.Thread.run(Thread.java:748)