input: Write a function to visualize Twitter data by summarizing the tweet authors, number of likes, and number of retweets. The function should return the visual plots for each summary.
  
  
  import matplotlib.pyplot as plt
  
  def summarize_twitter_data(twitter_data):
      # Extract relevant data fields from the Twitter data
      authors = [tweet['author'] for tweet in twitter_data]
      num_tweets = [twitter_data.count(tweet) for tweet in twitter_data]
      num_likes = [tweet['likes'] for tweet in twitter_data]
      num_retweets = [tweet['retweets'] for tweet in twitter_data]
      tweets = [tweet['text'] for tweet in twitter_data]
  
      # Plot the tweet authors
      plt.figure(1)
      plt.xlabel('Tweet Authors')
      plt.ylabel('Number of tweets')
      plt.title('Tweet Author Summary')
      plt.bar(authors, num_tweets)
      plt.show()
  
      # Plot the number of likes
      plt.figure(2)
      plt.xlabel('Tweets')
      plt.ylabel('Number of Likes')
      plt.title('Number of Likes Summary')
      plt.bar(tweets, num_likes)
      plt.show()
  
      # Plot the number of retweets
      plt.figure(3)
      plt.xlabel('Tweets')
      plt.ylabel('Number of Retweets')
      plt.title('Number of Retweets Summary')
      plt.bar(tweets, num_retweets)
      plt.show()
  
  # Test cases
  twitter_data = [
      {'author': 'User1', 'text': 'Tweet 1', 'likes': 10, 'retweets': 5, 'date': '2023-01-01'},
      {'author': 'User2', 'text': 'Tweet 2', 'likes': 20, 'retweets': 10, 'date': '2023-01-02'},
      {'author': 'User1', 'text': 'Tweet 3', 'likes': 15, 'retweets': 7, 'date': '2023-01-03'}
  ]
  summarize_twitter_data(twitter_data)
  
output: def summarize_twitter_data(twitter_data):
      authors = [tweet['author'] for tweet in twitter_data]
      num_tweets = [authors.count(author) for author in set(authors)]
      unique_authors = list(set(authors))
      num_likes = [tweet['likes'] for tweet in twitter_data]
      num_retweets = [tweet['retweets'] for tweet in twitter_data]
      tweets = [tweet['text'] for tweet in twitter_data]
  
      plt.figure(1)
      plt.xlabel('Tweet Authors')
      plt.ylabel('Number of tweets')
      plt.title('Tweet Author Summary')
      plt.bar(unique_authors, num_tweets)
      plt.show()
  
      plt.figure(2)
      plt.xlabel('Tweets')
      plt.ylabel('Number of Likes')
      plt.title('Number of Likes Summary')
      plt.bar(tweets, num_likes)
      plt.show()
  
      plt.figure(3)
      plt.xlabel('Tweets')
      plt.ylabel('Number of Retweets')
      plt.title('Number of Retweets Summary')
      plt.bar(tweets, num_retweets)
      plt.show()