How to install a win32 version of python using win64 anaconda

Question

I am trying to set up the covarep software on my win64 machine for a project and need to install 'a Windows 32-bit version of Python 2.7, 3.3, and/or 3.4'.

I used conda (platform win-64) to run conda create -n "covarep-env" python=3.4.0 -c free

This created an environment that has python version 3.4.0, but this obviously defaults to installing the win-64 version.

After following the covarep README instructions and running import covarep_py in python, I get the error

RuntimeError: To call deployed MATLAB code on a win32 machine, you must run a win32 version of Python. Details: C:\Program Files (x86)\MATLAB\MATLAB Runtime\v90\runtime\win32

Q: Is there a way to specify the win32 platform version of python when running conda create?

CristiFati · Accepted Answer · 2023-07-25T11:59:28.637

You must set the CONDA_FORCE_32BIT environment variable (got it from [YouTube]: DotPi - Create 32-bit Python Environments from a 64-bit Conda Installation) before creating the environment (not related to (previous) "environment variable").

Unfortunately the only official reference I could find is [Anaconda.Docs]: Troubleshooting - Using 32- and 64-bit libraries and CONDA_FORCE_32BIT.

Example (Anaconda Prompt - I used Python 3.6 as an example, as I need it for another task):

(base) [cfati@CFATI-5510-0:C:\Users\cfati]> :: Create a "regular" (pc064) environment
(base) [cfati@CFATI-5510-0:C:\Users\cfati]> conda create -n py_pc064_03_06_02 python=3.6.2
Collecting package metadata (current_repodata.json): done
Solving environment: failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): done
Solving environment: done


==> WARNING: A newer version of conda exists. <==
  current version: 4.14.0
  latest version: 22.9.0

Please update conda by running

    $ conda update -n base -c defaults conda



## Package Plan ##

  environment location: f:\Install\pc064\Anaconda\Anaconda\Version\envs\py_pc064_03_06_02

  added / updated specs:
    - python=3.6.2


The following NEW packages will be INSTALLED:

  certifi            pkgs/main/win-64::certifi-2021.5.30-py36haa95532_0
  pip                pkgs/main/win-64::pip-21.2.2-py36haa95532_0
  python             pkgs/main/win-64::python-3.6.2-h09676a0_15
  setuptools         pkgs/main/win-64::setuptools-58.0.4-py36haa95532_0
  vc                 pkgs/main/win-64::vc-14.2-h21ff451_1
  vs2015_runtime     pkgs/main/win-64::vs2015_runtime-14.27.29016-h5e58377_2
  wheel              pkgs/main/noarch::wheel-0.37.1-pyhd3eb1b0_0
  wincertstore       pkgs/main/win-64::wincertstore-0.2-py36h7fe50ca_0


Proceed ([y]/n)? y

Preparing transaction: done
Verifying transaction: done
Executing transaction: done
#
# To activate this environment, use
#
#     $ conda activate py_pc064_03_06_02
#
# To deactivate an active environment, use
#
#     $ conda deactivate

Retrieving notices: ...working... done

(base) [cfati@CFATI-5510-0:C:\Users\cfati]>
(base) [cfati@CFATI-5510-0:C:\Users\cfati]> :: SET ENVIRONMENT VARIABLE
(base) [cfati@CFATI-5510-0:C:\Users\cfati]> set CONDA_FORCE_32BIT=1

(base) [cfati@CFATI-5510-0:C:\Users\cfati]> :: Create a funky (pc032) environment
(base) [cfati@CFATI-5510-0:C:\Users\cfati]> conda create -n py_pc032_03_06_02 python=3.6.2
Collecting package metadata (current_repodata.json): done
Solving environment: failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): done
Solving environment: done

## Package Plan ##

  environment location: f:\Install\pc064\Anaconda\Anaconda\Version\envs\py_pc032_03_06_02

  added / updated specs:
    - python=3.6.2


The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    certifi-2021.5.30          |   py36h9f7ea03_0         140 KB
    pip-21.2.2                 |   py36h9f7ea03_0         1.8 MB
    python-3.6.2               |      hb0ff576_15        12.8 MB
    setuptools-58.0.4          |   py36h9f7ea03_0         777 KB
    vc-14.2                    |       h21ff451_1           8 KB
    vs2015_runtime-14.27.29016 |       h5e58377_2        1000 KB
    wheel-0.37.1               |     pyhd3eb1b0_0          33 KB
    wincertstore-0.2           |   py36hcdd9a18_0          14 KB
    ------------------------------------------------------------
                                           Total:        16.5 MB

The following NEW packages will be INSTALLED:

  certifi            pkgs/main/win-32::certifi-2021.5.30-py36h9f7ea03_0
  pip                pkgs/main/win-32::pip-21.2.2-py36h9f7ea03_0
  python             pkgs/main/win-32::python-3.6.2-hb0ff576_15
  setuptools         pkgs/main/win-32::setuptools-58.0.4-py36h9f7ea03_0
  vc                 pkgs/main/win-32::vc-14.2-h21ff451_1
  vs2015_runtime     pkgs/main/win-32::vs2015_runtime-14.27.29016-h5e58377_2
  wheel              pkgs/main/noarch::wheel-0.37.1-pyhd3eb1b0_0
  wincertstore       pkgs/main/win-32::wincertstore-0.2-py36hcdd9a18_0


Proceed ([y]/n)? y


Downloading and Extracting Packages
vc-14.2              | 8 KB      | ############################################################################ | 100%
vs2015_runtime-14.27 | 1000 KB   | ############################################################################ | 100%
certifi-2021.5.30    | 140 KB    | ############################################################################ | 100%
setuptools-58.0.4    | 777 KB    | ############################################################################ | 100%
wincertstore-0.2     | 14 KB     | ############################################################################ | 100%
pip-21.2.2           | 1.8 MB    | ############################################################################ | 100%
python-3.6.2         | 12.8 MB   | ############################################################################ | 100%
wheel-0.37.1         | 33 KB     | ############################################################################ | 100%
Preparing transaction: done
Verifying transaction: done
Executing transaction: done
#
# To activate this environment, use
#
#     $ conda activate py_pc032_03_06_02
#
# To deactivate an active environment, use
#
#     $ conda deactivate

Retrieving notices: ...working... done

(base) [cfati@CFATI-5510-0:C:\Users\cfati]> :: RESET ENVIRONMENT VARIABLE (to avoid any future problems in this terminal)
(base) [cfati@CFATI-5510-0:C:\Users\cfati]> set CONDA_FORCE_32BIT=

(base) [cfati@CFATI-5510-0:C:\Users\cfati]> conda env list
# conda environments:
#
                         F:\Install\pc032\Intel\OneAPI\Version\intelpython\python3.7
                         F:\Install\pc032\Intel\OneAPI\Version\intelpython\python3.7\envs\2021.1.1
base                  *  f:\Install\pc064\Anaconda\Anaconda\Version
py_pc032_03_06_02        f:\Install\pc064\Anaconda\Anaconda\Version\envs\py_pc032_03_06_02
py_pc064_03_06_02        f:\Install\pc064\Anaconda\Anaconda\Version\envs\py_pc064_03_06_02
py_pc064_03_08_08        f:\Install\pc064\Anaconda\Anaconda\Version\envs\py_pc064_03_08_08
py_pc064_03_10_00        f:\Install\pc064\Anaconda\Anaconda\Version\envs\py_pc064_03_10_00

Verify the created environments (check [SO]: How do I determine if my python shell is executing in 32bit or 64bit mode on OS X? (@CristiFati's answer) for more details):

(base) [cfati@CFATI-5510-0:C:\Users\cfati]> :: Activate pc064 env
(base) [cfati@CFATI-5510-0:C:\Users\cfati]> conda activate py_pc064_03_06_02

(py_pc064_03_06_02) [cfati@CFATI-5510-0:C:\Users\cfati]> python
Python 3.6.2 |Anaconda, Inc.| (default, Sep 30 2017, 11:52:29) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import ctypes as cts
>>> print(cts.sizeof(cts.c_void_p) * 8)
64
>>> ^Z


(py_pc064_03_06_02) [cfati@CFATI-5510-0:C:\Users\cfati]> conda deactivate

(base) [cfati@CFATI-5510-0:C:\Users\cfati]> :: Activate pc032 env
(base) [cfati@CFATI-5510-0:C:\Users\cfati]> conda activate py_pc032_03_06_02

(py_pc032_03_06_02) [cfati@CFATI-5510-0:C:\Users\cfati]> python
Python 3.6.2 |Anaconda, Inc.| (default, Sep 30 2017, 11:44:55) [MSC v.1900 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import ctypes as cts
>>> print(cts.sizeof(cts.c_void_p) * 8)
32
>>> ^Z


(py_pc032_03_06_02) [cfati@CFATI-5510-0:C:\Users\cfati]> conda deactivate

(base) [cfati@CFATI-5510-0:C:\Users\cfati]>

This worked like a charm, thank you! Video was also super helpful — bgmn, Nov 20 '22 at 14:49

How to install a win32 version of python using win64 anaconda

1 Answers1