pip install beautifulsoup4.失败

在学习python爬虫时，用到bs4解析网页，开始遇到安装bs出错

Collecting beautifulsoup4
Exception:
Traceback (most recent call last):
  File "g:\python27\lib\site-packages\pip\basecommand.py", line 215, in main
    status = self.run(options, args)
  File "g:\python27\lib\site-packages\pip\commands\install.py", line 324, in ru

requirement_set.prepare_files(finder)
  File "g:\python27\lib\site-packages\pip\req\req_set.py", line 380, in prepare
files
    ignore_dependencies=self.ignore_dependencies))
  File "g:\python27\lib\site-packages\pip\req\req_set.py", line 620, in _prepar
_file
    session=self.session, hashes=hashes)
  File "g:\python27\lib\site-packages\pip\download.py", line 821, in unpack_url
    hashes=hashes
  File "g:\python27\lib\site-packages\pip\download.py", line 659, in unpack_htt
_url
    hashes)
  File "g:\python27\lib\site-packages\pip\download.py", line 880, in _download_
ttp_url
    file_path = os.path.join(temp_dir, filename)
  File "g:\python27\lib\ntpath.py", line 85, in join
    result_path = result_path + p_path
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc1 in position 7: ordinal
not in range(128)

解决方法：

原因：pip安装python包会加载用户目录，用户目录恰好是中文的，ascii不能编码。解决办法是： 
  
python目录 Python27\Lib\site-packages 建一个文件sitecustomize.py 
  
内容写： 
   
import sys 
   
sys.setdefaultencoding('gb2312')