It's best to install python using the "all users" option. The Environment Variable paths are normal and were automatically added when each version of python was installed. Whatever the version of python, it will start from the Command prompt. This is a simple and elegant solution to easily run 2 or more different versions of python without using scripts in Windows. If none of this works then restart the computer and if the problem still persists then uninstall everything and repeat the steps. Once you are in there type python or py, It should open up python3.ĥ)Now exit out of python3 by typing exit(). Now click on OK and you should be done.Ĥ)Now to test this open the command prompt. Right click on my computer-Go to properties-Select advanced system settings-Go to environment variables-Click on new under System variables and add a new system variable with variable name as PY_PYTHON and set this variable value to 3. For python 2 open up your python 2 installer, select whatever preferences you want but just remember to set Add python.exe to path to Will be installed on local hard drive, Now just click next and wait for the installer to finish.ģ)When both the installations are complete. The easiest way to run multiple versions of python on windows is described below as follows:-ġ)Download the latest versions of python from /downloads by selecting the relevant version for your system.Ģ)Run the installer and select Add python 3.x to the path to set path automatically in python 3 (you just have to click the checkbox). On Windows you don't get a global python command as far as I know so that's not an issue. Note the "altinstall" that means it will install it, but it will not replace the python command. But if you don't want to do that, and you probably don't you can install it like this. This is mostly not a problem as most scripts will explicitly call /usr/local/bin/python2.5 or something just to protect against that. When you install on Unix (including Linux and OS X) you will get a generic python command installed, which will be the last one you installed. On Windows Unix (including Linux and OS X). For example: C:\Python2.5\Python.exeįor Python 2.5 on windows and C:\Python2.6\Python.exeįor Python 2.6 on windows, or /usr/local/bin/python-2.5 Then you call the Python version you want. So installing Python 2.5.x will not overwrite Python 2.6.x, although installing 2.6.6 will overwrite 2.6.5. When you install Python, it will not overwrite other installs of other major versions. Then you can activate the first and work with Python 2.5 like thisĪnd when you want to switch to Python 2.6 you do deactivate Virtualenv -p c:\python2.6\python.exe c:\venvs\2.6 Virtualenv -p c:\python2.5\python.exe c:\venvs\2.5 Install virtualenv and create two virtualenvs.Or instead of running python command run pylauncher command ( py) specyfing which version of Python you want #! c:\\python.exe - for scripts you want to be run with Python 2.6 #! c:\\python.exe - for scripts you want to be run with Python 2.5 Use pylauncher (if you have Python 3.3 or newer there's no need to install it as it comes with Python already) and either add shebang lines to your scripts.The other alternative is to create a shortcut to the respective python.exe calling one of them python25 and the other python26 you can then simply run python25 on your command line.Īdding two more solutions to the problem: What you really need to do is to explicitly call one or both of the applications, such as c:\python\2.5\python.exe or c:\python\2.6\python.exe. Now, if you've installed two python versions 2.5 and 2.6, the path will have both of their directories in it, something like PATH=c:\python\2.5 c:\python\2.6 but Windows will stop examining the path when it finds a match. When it finds the correct file to run the file is being run. cmd) or some other executable to run (this is controlled by the PATHEXT environment variable), that matches the name given. What this does under Windows, is to trawl the %PATH% environment variable, checking for an executable, either batch file (. You mention that you've started a python instance, from the command line, by simply typing python. Running a different copy of Python is as easy as starting the correct executable.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |