什么是Pyspark中的RegExP_Replace和Length函数等效

Question

我只是让自己熟悉pyspark。      澄清，什么是RegExp_Replace oracle等效项
      在Pyspark。
      还有什么是pyspark中的Length函数

 I've tried using Length function in Pyspark and isn't working but 
 for RegExp_Replace not sure what to use as alternative  

Df.withcolumn(Length(col("Emp_code"))).show()  
DF.REGREPLACE.Trim('Emp_Code'),'\d')  

  The above length code is resulting in an error  

    Withcoulmn() 
    missing one positional requirement argument: col