Hi @zll_0091 ,

Could you provide more code? What's inside dsfd variable? What's your expected outcome?

Hi Slash,

dsfd is just dbutils.fs.ls of my source path.

Output: [Column<'substring(process_run_key=661962868/, 16, 26)'>]

Expected Output: [661962868]

I just want to get the integer of that specific folder.

So, in my opinion you're doing it wrong. The dbutils.fs.ls will return python list. You're using substring function from pyspark.sql.functions which is not needed in this case.
As an example, I created dsfd variable with following content

Then I can iterate over this list in the following way. Let's say that I only need path from dbutils.fs.ls output:

for row in dsfd:
    print(row.path)