Python 2.7.x使用pip报错

问题描述

由于某些作业的需求，我不得不使用 python 2.7.x（甚至是跑人工智能，甚至还在用python2，真是吃不消了），用 conda 创建完 python 2.7.x 的环境后准备用 pip 安装软件包，然后就开始疯狂报错orz

报错内容如下：

(ai1) PS D:\JetBrains\JetbrainProjects\PyCharmProjects\AI\lab1> pip install scipy==0.18.1
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Collecting scipy==0.18.1
ERROR: Exception:
Traceback (most recent call last):
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\cli\base_command.py", line 153, in _main
    status = self.run(options, args)
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\commands\install.py", line 382, in run
    resolver.resolve(requirement_set)
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\legacy_resolve.py", line 201, in resolve
    self._resolve_one(requirement_set, req)
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\legacy_resolve.py", line 365, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\legacy_resolve.py", line 313, in _get_abstract_dist_for
    req, self.session, self.finder, self.require_hashes
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\operations\prepare.py", line 194, in prepare_linked_requirement
    progress_bar=self.progress_bar
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\download.py", line 465, in unpack_url
    progress_bar=progress_bar
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\download.py", line 316, in unpack_http_url
    progress_bar)
  File "D:\Code_about\Anaconda3\envs\ai1\lib\site-packages\pip\_internal\download.py", line 549, in _download_http_url
    file_path = os.path.join(temp_dir, filename)
  File "D:\Code_about\Anaconda3\envs\ai1\lib\ntpath.py", line 85, in join
    result_path = result_path + p_path
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd6 in position 7: ordinal not in range(128)

解决方案

前面的几行都是让你不要再用 python 2.7 了（废话，我也不想用啊），下面是报错信息，我们可以看到是发生在一个路径合并函数中，需要 ascii 字符，但是检测到了非 ascii 字符，这bug . . . . . . 挺邪门啊。

原因是 python2 默认编码是 ascii ，而 pip 把下载的临时文件存放在了用户临时文件中，如果用户名是中文自然就有非 ascii 字符，因此会报错了。

解决方法是找到 python2.7 目录下的 Lib 文件夹中的 ntpath.py 文件（如果是使用 anaconda 虚拟环境的话，这个文件的路径是： \envs\{{env_name}}\Lib\ntpath.py），打开，找到 def join(path, *paths) 方法，在下面添加两行代码：