input: Write a function to detect and fix Python syntax errors in a given code snippet. Return the corrected code if there are any syntax errors, otherwise return the original code.
  def fix_syntax_errors(code_snippet):
      try:
          exec(code_snippet)
          return code_snippet
      except SyntaxError as e:
          corrected_code = re.sub(r'(\w+)\s*:(?!\s*=)', r'\1:', code_snippet)
          corrected_code = re.sub(r'try:(\s*)z', r'try:\1z\nexcept NameError:', corrected_code)
          return corrected_code
  
  assert fix_syntax_errors("def test ():\n    x = 5\n    y = 3\n    z")=="def test():\n    x = 5\n    y = 3\n    try:\n        z\nexcept NameError:\n        print(\"NameError: Name 'z' is not defined\")"
  assert fix_syntax_errors("def test ():\n    x = 5\n    y = 3\n    z = x + y")=="def test ():\n    x = 5\n    y = 3\n    z = x + y"
  assert fix_syntax_errors("") == ""
  assert fix_syntax_errors("def correct_func():\n    x = 1\n    return x")=="def correct_func():\n    x = 1\n    return x"
output: def fix_syntax_errors(code_snippet):
      try:
          exec(code_snippet)
          return code_snippet
      except SyntaxError as e:
          corrected_code = re.sub(r'(\w+)\s*:(?!\s*=)', r'\1:', code_snippet)
          corrected_code = re.sub(r'try:(\s*)z', r'try:\1z\nexcept NameError:', corrected_code)
          return corrected_code