How to rebuild virtualenvs after deleting associated python interpreter

Question

I have a number of django projects organized with the following directory structure using win7 (I'm using GIT_BASH/mingw for my command line) :

envs--r1--project1
        --project2
        --Include
        --Library
        --Scripts--python.exe
python275--

The idea being here that the different projects have a common environment and I can activate that environment from each projects root directory using:

$ source ../Scripts/activate

I don't understand exactly how it happened but it turned out that the interpreter ( listed above as python.exe ) was linked somehow to a second python folder above.

I deleted the python275 folder ( AAHH!!) , not realizing its importance, resulting in:

Traceback (most recent call last): File "C:\envs\r1\lib\site.py", line 703, in   main() File "C:\envs\r1\lib\site.py", line 692, in main aliasmbcs() File "C:\envs\r1\lib\site.py", line 515, in aliasmbcs import locale, codecs File "C:\envs\r1\lib\locale.py", line 19, in   import functools ImportError: No module named functools

I have reinstalled the correct python folder but the error persists. Can anyone advise me on how to rebuild the virtualenvs so I can go back to the way it was?

edit:

(r1)
/C/envs/r1/Scripts
$ import reload(functools)
sh: syntax error near unexpected token `('
(r1)
/C/envs/r1/Scripts
$ python.exe import reload(functools)
sh: syntax error near unexpected token `('
(r1)
/C/envs/r1/Scripts
$ python.exe reload functools        
Traceback (most recent call last):
  File "C:\envs\r1\lib\site.py", line 703, in <module>
    main()
  File "C:\envs\r1\lib\site.py", line 692, in main
    aliasmbcs()
  File "C:\envs\r1\lib\site.py", line 515, in aliasmbcs
    import locale, codecs
  File "C:\envs\r1\lib\locale.py", line 19, in <module>
    import functools
ImportError: No module named functools


(r1)
/C/envs/r1/Scripts
$ reload(functools)
sh: syntax error near unexpected token `('
(r1)
/C/envs/r1/Scripts
$ python.exe reload(functools)
sh: syntax error near unexpected token `('
(r1)


/C/envs/r1/Scripts
$ python.exe  test.py
Traceback (most recent call last):
  File "f:\envs\r1\lib\site.py", line 703, in <module>
    main()
  File "f:\envs\r1\lib\site.py", line 692, in main
    aliasmbcs()
  File "f:\envs\r1\lib\site.py", line 515, in aliasmbcs
    import locale, codecs
  File "f:\envs\r1\lib\locale.py", line 19, in <module>
    import functools
ImportError: No module named functools

i think you need reload functools where that `import functools` is ! and change it to `import reload(functools)` — Mazdak, Sep 19 '14 at 18:36
Sorry, I'm pretty new to python. would you mind explaining further? What and where is functools ? — user1592380, Sep 19 '14 at 18:56
as in your `Traceback ` error says you have this import error `ImportError: No module named functools` so in python if you change a module or delete and built it again you need to reload module so i suggest reload `functools` i think its in this path `ImportError: No module named functools` — Mazdak, Sep 19 '14 at 19:00
add `reload(functools)` above of `import functools` than give me the result ! — Mazdak, Sep 19 '14 at 19:15
I'm not sure I understand what you are saying correctly. I've created a new file called test.py and tried both: "reload(functools.py)" and "reload(functools)" in it. the I ran it. Please see above: — user1592380, Sep 20 '14 at 13:27
As we can see from the stacktrace, the error occurs before test.py is executed. could you check if the lib directory has the file `functools.py` it is one of the python modules that is imported by the interpreter before executing any file? — srj, Sep 23 '14 at 19:56
this advice to reload functools, in python code, makes no sense to me — Anentropic, Sep 26 '14 at 17:15

Anton Strogonoff · Accepted Answer · 2014-09-29T13:55:25.217

I suggest reinstalling Python and virtualenv from scratch in your case, and then re-creating the environment(s).

Make sure you have a working Python 2.7.5 installation on your system.
Make sure you have pip installed (see docs).
Make sure pip is linked to the Python installation above (check the output of pip -V, it should contain the correct system-wide Python path).
Do a clean install of virtualenv using pip install virtualenv.
Create and activate the environment for your projects.
Reinstall within your new environment all the modules you had installed in your old environment.

This may be a tricky one.
- If you have an up-to-date file such as requirements.txt with all the packages required, then you're all set (pip install -r requirements.txt should do it).
- If you don't have requirements listed, or they aren't up-to-date, then check manually which packages you had installed in your old environment. For that you should locate site-packages directory within your old virtualenv (should be under Library probably) and look what's in there. Every non-system package you recognize in site-packages directory you install into your new environment (normally using pip install but some packages may have custom instructions).

That's what I did when it happened to me. I wasn't able to simply rebuild the environment, so I did the reinstall for cleanness.

Thank you , I used a variant of your answer to fix my problem. — user1592380, Sep 29 '14 at 19:05

score 2 · Answer 2 · edited May 23 '17 at 11:58

2

Taken from other post. You can associate the virtualenv to a python version.

You indicate the Python interpreter to use with the flag -p or --python (e.g --python=python2.5)

    virtualenv -p /usr/bin/python2.6 <path/to/new/virtualenv/>

But this is just works for creating new environments. You would need to access your old virtualenv and execute:

     pip freeze > requirements.txt

The file requirements.txt would contain all the apps you installed in the old virtual environment and their respective versions. Now, from the new environment you have created, run:

     pip install -r requirements.txt

You should active the virtual environment.

     $ source /yourvirtualenvpath/bin/activate

     $ pip freeze > /home/user/requirements.txt

     $ deactivate 

     $ source /yourNEWvirtualenvpath/bin/activate

     $ pip install -r /home/user/requirements.txt

edited May 23 '17 at 11:58

Community

1
1

answered Sep 24 '14 at 09:55

Emily

316
2
9

Emily , thanks for looking at this. What directory should I execute the pip freeze from? – user1592380 Sep 24 '14 at 14:13
Thanks Emily, when I do the pip freeze I get "ImportError: No module named functools" just like above. – user1592380 Sep 24 '14 at 19:31
At this point I'm beginning to suspect that I corrupted something when I deleted the python275 folder. If someone could show me how to rebuild from scratch using newly installed python275 folder as the interpreter I would accept this as an answer. - Bill – user1592380 Sep 26 '14 at 00:23
Sorry I couldn't answer before, check this post, seems like the same problem you're having: http://stackoverflow.com/questions/16786287/changing-virtualenv-folder-on-windows – Emily Sep 26 '14 at 08:57
Thanks for your hard work on this. it didn't hrlp me but I'm awarding the bounty to you – user1592380 Sep 29 '14 at 19:05

How to rebuild virtualenvs after deleting associated python interpreter

2 Answers2