input: Write a python function to load a CSV file and preprocess the data by adding a new column 'is_recent' based on whether the 'date' is within the last day.
  assert preprocess_data('posts.csv').iloc[0]['is_recent'] == (pd.to_datetime('2023-10-01') - pd.to_datetime('2023-09-30')).days <= 1
  assert preprocess_data('posts.csv').iloc[1]['is_recent'] == (pd.to_datetime('2023-10-02') - pd.to_datetime('2023-09-30')).days <= 1
output: import pandas as pd
  
  def preprocess_data(file_path):
      # Load the CSV file
      df = pd.read_csv(file_path)
      
      # Convert the 'date' column to datetime
      df['date'] = pd.to_datetime(df['date'])
      
      # Get the current date
      current_date = pd.to_datetime('now')
      
      # Add 'is_recent' column
      df['is_recent'] = (current_date - df['date']).days <= 1
      
      return df