由于某些原因，当我运行“ brew link
python”时，它不是符号链接。我收到以下错误，并且按提示操作去做，但是没有用。我已经尝试执行它告诉我的操作，但是也许我没有正确设置Formula_name。另外，当我执行“哪个python”时，它并不指向Homebrew
python，我也需要帮助修复它。

    Linking /usr/local/Cellar/python/2.7.3...Warning: Could not link python. 
    Unlinking....

   Error: Could not symlink file: /usr/local/Cellar/python/2.7.3/bin/smtpd.py
   Target /usr/local/bin/smtpd2.py already exists. You may need to delete it.
   To force the link and delete this file, do:
      brew link --overwrite formula_name