尝试升级pip后，为什么会收到DistributionNotFound错误？

Question

运行yolk -U最近我注意到，pip需要升级从1.2.1到1.4.1，并忠实地尝试与

pip install --upgrade pip 

虽然运行yolk -U升级再次出现确认成功升级（pip不再列为即将过期的），这产生的错误信息

Downloading/unpacking pip from https://pypi.python.org/packages/source/p/pip/pip-1.4.1.tar.gz#md5=6afbb46aeb48abac658d4df742bff714 
Downloading pip-1.4.1.tar.gz (445kB): 445kB downloaded 
Running setup.py egg_info for package pip 

    warning: no files found matching '*.html' under directory 'docs' 
    warning: no previously-included files matching '*.rst' found under directory 'docs/_build' 
    no previously-included directories found matching 'docs/_build/_sources' 
Installing collected packages: pip 
    Found existing installation: pip 1.2.1 
    Uninstalling pip: 
Exception: 
Traceback (most recent call last): 
    File "/Library/Python/2.7/site-packages/pip-1.2.1-py2.7.egg/pip/basecommand.py", line 107, in main 
    File "/Library/Python/2.7/site-packages/pip-1.2.1-py2.7.egg/pip/commands/install.py", line 261, in run 
    File "/Library/Python/2.7/site-packages/pip-1.2.1-py2.7.egg/pip/req.py", line 1162, in install 
    File "/Library/Python/2.7/site-packages/pip-1.2.1-py2.7.egg/pip/req.py", line 495, in uninstall 
    File "/Library/Python/2.7/site-packages/pip-1.2.1-py2.7.egg/pip/req.py", line 1492, in remove 
    File "/Library/Python/2.7/site-packages/pip-1.2.1-py2.7.egg/pip/util.py", line 273, in renames 
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 299, in move 
os.unlink(src) 
OSError: [Errno 13] Permission denied: '/usr/local/bin/pip' 

而且我所有的后续尝试使用pip做的一样好：

Traceback (most recent call last): 
    File "/usr/local/bin/pip", line 5, in <module> 
    from pkg_resources import load_entry_point 
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources.py", line 2603, in <module> 
    line, p, specs = scan_list(VERSION,LINE_END,line,p,(1,2),"version spec") 
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources.py", line 666, in require 
    continue # try the next older version of project 
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources.py", line 565, in resolve 

pkg_resources.DistributionNotFound: pip==1.2.1 

我看到类似问题have been reported之前，但没有任何我看到的建议帮助解决此问题。

我被卡住了，无法维护我的Python安装。

---

我在使用OS 10.8.4，Python 2.7.2在/usr/bin/python。

Answer 1

根据这条线：

OSError: [Errno 13] Permission denied: '/usr/local/bin/pip' 

这似乎是一个* nix的权限问题，请尝试使用sudo来启动升级：

sudo pip install --upgrade pip 

在一个侧面说明，我推荐使用这种升级方法：http://www.pip-installer.org/en/latest/installing.html#install-or-upgrade-pip

TL;博士版本（这要感谢OP提供的信息;））：

1.Download和http://www.pip-installer.org/en/latest/installing.html#install-or-upgrade-pip

laucnh get-pip.py 2.如果你得到关于“无效的命令‘egg_info’”的错误，你需要使用升级设置工具PIP安装--upgrade的setuptools或easy_install -U