Windows Command Line Python Change Version

Question

New to Python and programming in general. I want to "install" a module from the command line for v 2.6, but it looks like my default Python is 2.5. (python --version returns 2.5.4)

How can I run my python setup.py build/install on 2.6 instead?

Many thanks in advance,

Brock

Does this answer your question? [How to run multiple Python versions on Windows](https://stackoverflow.com/questions/4583367/how-to-run-multiple-python-versions-on-windows) — user202729, Jan 24 '21 at 13:59

Mark Tolonen · Answer 1 · 2016-09-28T13:02:35.657

You can use explicit paths:

c:\python26\python setup.py install
c:\python25\python setup.py install

Recent versions of Python install PyLauncher. It is installed in the path so no need to add an explicit Python to the path, and it allows easy switching between multiple Python versions.

Examples:

py -3 setup.py # run latest Python 3
py -2 setup.py # run latest Python 2
py -3.3
py -2.7-32 # use 32-bit version
py # run default version

The default version can be specified in the environment variable PY_PYTHON, e.g. PY_PYTHON=3 (latest Python 3).

score 4 · Answer 2 · answered Jan 06 '15 at 14:38

If you're on Windows and you just need to run a different version of Python temporarily or, as was the case for me, a third party program needs to run a different version of Python, then modify your path at the command prompt:

> python --version
> set PATH=<path-to-desired-python-version>;%PATH%
> python --version

For me it was:

> python --version
Python 3.4.2
> set PATH=C:\tools\python2\;%PATH%
> python --version
Python 2.7.9
> npm install...
(success)

This allowed the third party program to install successfully. The PATH modification only affects programs running in the same command prompt session and only lasts as long as the command prompt session..

score 4 · Accepted Answer · answered Jul 06 '10 at 18:46

4

It depends on your operating system. If you have python 2.6 installed, you need to change your environment path to point to the 2.6 executable rather than the 2.5 executable. Do a Google search for changing your PATH variable on your operating system.

answered Jul 06 '10 at 18:46

Alex Bliskovsky

5,973
7
32
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Just for reference: this was a great help http://people.cis.ksu.edu/~schmidt/301f09/setpath.html – Btibert3 Jul 06 '10 at 20:29

score 1 · Answer 4 · answered May 21 '17 at 16:53

1

They are a couple of ways you can do this 1) python virtual environment 2) pylauncher 3) Changing your windows path variable, tedious to say the least

All three outlined in this video https://www.youtube.com/watch?v=ynDlb0n27cw

answered May 21 '17 at 16:53

Timothy Mugayi

1,449
17
11

score 0 · Answer 5 · answered Apr 09 '12 at 02:20

It sounds like you are on windows. If so, run this with the python you want, to set that python as the windows one. (not my code)

import sys

from _winreg import *

# tweak as necessary
version = sys.version[:3]
installpath = sys.prefix

regpath = "SOFTWARE\\Python\\Pythoncore\\%s\\" % (version)
installkey = "InstallPath"
pythonkey = "PythonPath"
pythonpath = "%s;%s\\Lib\\;%s\\DLLs\\" % (
    installpath, installpath, installpath
)

def RegisterPy():
    try:
        reg = OpenKey(HKEY_LOCAL_MACHINE, regpath)
    except EnvironmentError:
        try:
            reg = CreateKey(HKEY_LOCAL_MACHINE, regpath)
        except Exception, e:
            print "*** Unable to register: %s" % e
            return

    SetValue(reg, installkey, REG_SZ, installpath)
    SetValue(reg, pythonkey, REG_SZ, pythonpath)
    CloseKey(reg)
    print "--- Python %s at %s is now registered!" % (version, installpath)

if __name__ == "__main__":
    RegisterPy()

Windows Command Line Python Change Version

5 Answers5