input: Write a function to re-write the given SQL query in Python. The function should connect to an SQLite database named 'movies.db', execute the given SQL query to select all rows from the 'Movies' table where the 'category' is 'horror', fetch and print the results, and then close the database connection.
  assert execute_query()
output: def execute_query():
      import sqlite3
      conn = sqlite3.connect('movies.db')
      cursor = conn.cursor()
      cursor.execute("SELECT * FROM Movies WHERE category = 'horror'")
      results = cursor.fetchall()
      for row in results:
          print(row)
      conn.close()