code: def delete_if_exists(filename):
      if os.path.exists(filename):
          if os.path.isdir(filename):
              shutil.rmtree(filename)
          else:
              os.remove(filename)
  
file_path: pipelinedp/examples/restaurant_visits/run_on_dataframes.py
imports: from absl import app
  from absl import flags
  import os
  import shutil
  import pandas
  from pyspark.sql import SparkSession
  import pyspark
  import apache_beam
  from apache_beam.runners.portability import fn_api_runner
  from apache_beam.dataframe.io import read_csv
  import pipeline_dp
  from pipeline_dp import dataframes
  from typing import Union
label_desc: Use image node_id 1 for calling a global function with example usage: delete_if_exists(filename) without return types