input: def fix_syntax_errors(code_snippet: str) -> str:
      """
      Given a Python code snippet as a string, detect and fix syntax errors. This includes handling cases where variables are used before being defined and other common syntax mistakes.
  
      >>> 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\\n    except NameError:\\n        print("NameError: Name \'z\' is not defined")'
      """
output:     try:
          exec(code_snippet)
      except NameError as e:
          var_name = str(e).split("'")[1]
          code_snippet = code_snippet.replace(var_name, f'try:\n        {var_name}\n    except NameError:\n        print("NameError: Name \'{var_name}\' is not defined")')
      return code_snippet