input: Write a function to create a recommendation system in Python using Pandas to recommend new products to customers based on past purchases. Use the NearestNeighbors algorithm from sklearn.neighbors to implement the recommendation system. The function should read data from a CSV file, create an item-based collaborative filter, and print the indices of the nearest neighbors for each item. If the input data is empty or if there are any issues with reading the CSV file, the function should handle these cases appropriately.
  
  
  import pandas as pd
  from sklearn.neighbors import NearestNeighbors
  
  def recommend_products(csv_file):
      try:
          # Read in data
          data = pd.read_csv(csv_file)
          
          # Check if data is empty
          if data.empty:
              raise ValueError("The input data is empty.")
          
          # Create an item-based collaborative filter
          cf = NearestNeighbors(metric='cosine', algorithm='brute')
          cf.fit(data)
          
          # Make recommendations
          distances, indices = cf.kneighbors(data, n_neighbors=3)
          
          # Print results 
          for i in range(len(data)):
              print('Recommendations for item {}:'.format(i), indices[i])
          
          return True
      except Exception as e:
          print(f"An error occurred: {e}")
          return False
  
  assert recommend_products('test_product_data.csv')==True
  assert recommend_products('empty_data.csv')==False
  assert recommend_products('nonexistent_file.csv')==False
  
output: 
  def recommend_products(csv_file):
      try:
          data = pd.read_csv(csv_file)
          if data.empty:
              raise ValueError("The input data is empty.")
          cf = NearestNeighbors(metric='cosine', algorithm='brute')
          cf.fit(data)
          distances, indices = cf.kneighbors(data, n_neighbors=3)
          for i in range(len(data)):
              print('Recommendations for item {}:'.format(i), indices[i])
          return True
      except Exception as e:
          print(f"An error occurred: {e}")
          return False
  