Problem with django installation [python]

问题:

Last summer I wanted to learn to do web dev, so I installed Django 1.8, an unstable release. I installed it without pip. I recently decided to try again, but wanted to do work with the stable release, 1.7.1, and wanted to install with pip for simplicity.

I read that in order to remove Django that was installed without pip, one must delete the entire .egg from /Library/Python/2.7/site-packages/, so I did this.

Since then, I've been getting funny errors. When I issue 'pip install django', I get

bash-3.2$ pip install django
Downloading/unpacking django
  Downloading Django-1.7.1-py2.py3-none-any.whl (7.4MB): 7.4MB downloaded
Installing collected packages: django
Cleaning up...
Exception:
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/basecommand.py", line 122, in main
    status = self.run(options, args)
  File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/commands/install.py", line 283, in run
    requirement_set.install(install_options, global_options, root=options.root_path)
  File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/req.py", line 1435, in install
    requirement.install(install_options, global_options, *args, **kwargs)
  File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/req.py", line 671, in install
    self.move_wheel_files(self.source_dir, root=root)
  File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/req.py", line 901, in move_wheel_files
    pycompile=self.pycompile,
  File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/wheel.py", line 215, in move_wheel_files
    clobber(source, lib_dir, True)
  File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/wheel.py", line 205, in clobber
    os.makedirs(destdir)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 13] Permission denied: '/Library/Python/2.7/site-packages/django'

When I check the spurious directory, I find that /django doesn't exist. Issuing sudo will silence the errors, but I find that I still can't start a django project.

Has anyone seen this before or have any idea how to fix this?

回答1:

This is not really an error - as your normal user account cannot write to the global /Library folder, you are getting this permission denied error from the operating system.

The best practice is to work in a virtual environment called virtualenv for short. This makes sure that when you are experimenting with Python packages, you don't accidentally corrupt the system-wide installation of Python.

On a Mac (which you are using) there might be other system utilities that rely on Python and they may stop working if the system default Python is corrupted.

So the first step is to install virtualenv globally on your system. To do this, you need superuser permissions but this is done only once:

sudo easy_install virtualenv

The above will ask for a password - just enter your normal user password.

Once the above command finishes, as your normal user run the following from the command line:

$ virtualenv my_env  # This creates a new Python environment called my_env, completely
                     # separate from your system wide install.
$ source my_env/bin/activate # Activates the virtual envrionment
(my_env) $ pip install django # Install django in this new environment the (my_env)
                              # indicates you are working inside a virtual environment

...

(my_env) $ deactivate  # Deactivates the environment,
                       # returning you to the normal system Python
$

Anything you install in the virtual environment is only available within the virtual environment, so you need to make sure you are in the correct environment when running your scripts.

回答2:

I figured it out. I had to go to /usr/local/bin/ and delete all references to my django 1.8 install (django-admin, etc.), then follow the directions to install virtualenvwrapper and work within a virtual environment.

回答3:

To avoid virtualenv, I recommend pip install --user Django for Mac OS,

which installs the package in a location similar to:

~/Library/Python/2.7/lib/python/site-packages

From pip install --help:

--user                      Install to the Python user install directory for your platform. Typically ~/.local/, or %APPDATA%\Python on Windows.
                              (See the Python documentation for site.USER_BASE for full details.)

---

Then again virtualenv and virtualenvwrapper are the recommended method to install Django, I think?

回答4:

first, need to set up a virtual environment or a workon and activate it.

pip install Django

or

pip install -U Django

or

pip install -e django

回答5:

Windows user: start power shell as (Run as Administrator) or Start CMD as (Run as Administrator) after run the following command

For latest version:

pip install Django

Or for Previous release version e.g. 2.2

pip install Django==2.2

回答6:

Run the following command:

sudo pip install Django