input: Write a function that modifies a given Python program by adding a positive feedback loop to it. The function should take a string of Python code as input and return a string of modified Python code with the feedback loop added. The feedback loop should increase the loop counter each time and print a specific message when the loop completes.
  assert feedback_loop("for i in range(10):\n    print('hello')") == "for i in range(10):\n    print('hello')\n    i += 1\n    if i == 10:\n        print('You've got it!')"
  assert feedback_loop("for i in range(5):\n    print('hi')") == "for i in range(5):\n    print('hi')\n    i += 1\n    if i == 5:\n        print('You've got it!')"
  assert feedback_loop("") == ""
  assert feedback_loop("for i in range(3):\n    print('bye')") == "for i in range(3):\n    print('bye')\n    i += 1\n    if i == 3:\n        print('You've got it!')"
  assert feedback_loop("for i in range(0):\n    print('nothing')") == "for i in range(0):\n    print('nothing')\n    i += 1\n    if i == 0:\n        print('You've got it!')"
output: def feedback_loop(code):
      import re
      pattern = re.compile(r'for\s+i\s+in\s+range\((\d+)\):')
      match = pattern.search(code)
      if match:
          limit = int(match.group(1))
          if limit > 0:
              modified_code = pattern.sub(r'for i in range(\1):\n    i += 1\n    if i == \1:\n        print("You\'ve got it!")', code)
              return modified_code
      return code