I have version 2.7 installed from early 2012. I can't find any consensus on whether I should completely uninstall and wipe this version before putting on the latest version.
"Soft"-removing old versions? Hard-removing/wiping old versions? Installing over top?
I've seen somewhere a special install/upgrade process using a "segmenting" method of Python installations, keeping different versions separate and apart, but functional. Not sure if this is the standard, de facto way.
I also wonder if Revo gets too overzealous and may cause issues with wiping out still-needed remnants, like environment/PATH variables.
(Win7 x64, 32-bit Python)
As @cxw comments below, these answers are for the same bit-versions, and by bit-version I mean 64-bit vs. 32-bit. For example, these answers would apply to updating from 64-bit Python-2.7.10 to 64-bit Python-2.7.11, ie: the same bit-version. While it is possible to install two different bit versions of Python together, it would require some hacking, so I'll save that exercise for the reader. If you don't want to hack, I suggest that if switching bit-versions, remove the other bit-version first.
PATHand Registry. After extraction, create a symlink to
binor install conda from PyPI. Then create another symlink called
activatein the Anaconda/Miniconda root bin folder. Now Anaconda/Miniconda is just like Ruby RVM. Just use
conda-activate rootto enable Anaconda/Miniconda.
$ ln /c/Python33/python.exe python3).
If OP has 2.7.x and wants to install newer version of 2.7.x, then
It is recommended to uninstall any other Python distribution before installing Python(x,y)
home\AppData\Local\Enthought\Canopy\Appfor all users or per user respectively. Newer installations are updated by using the built in update tool. See their documentation.
Other Python 2.7 Installations On Windows, ActivePython 2.7 cannot coexist with other Python 2.7 installations (for example, a Python 2.7 build from python.org). Uninstall any other Python 2.7 installations before installing ActivePython 2.7.
conda update conda conda update anaconda
Anaconda/Miniconda lets users create environments to manage multiple Python versions including Python-2.6, 2.7, 3.3, 3.4 and 3.5. The root Anaconda/Miniconda installations are currently based on either Python-2.7 or Python-3.5.
Anaconda will likely disrupt any other Python installations. Installation uses MSI installer.
[UPDATE: 2016-05-16] Anaconda and Miniconda now use
.exe installers and provide options to disable Windows
PATH and Registry alterations.
Therefore Anaconda/Miniconda can be installed without disrupting existing Python installations depending on how it was installed and the options that were selected during installation. If the
.exe installer is used and the options to alter Windows
PATH and Registry are not disabled, then any previous Python installations will be disabled, but simply uninstalling the Anaconda/Miniconda installation should restore the original Python installation, except maybe the Windows Registry
Anaconda/Miniconda makes the following registry edits regardless of the installation options:
HKCU\Software\Python\ContinuumAnalytics\ with the following keys:
PythonPath - official Python registers these keys too, but under
Python\PythonCore. Also uninstallation info is registered for Anaconda\Miniconda. Unless you select the "Register with Windows" option during installation, it doesn't create
PythonCore, so integrations like Python Tools for Visual Studio do not automatically see Anaconda/Miniconda. If the option to register Anaconda/Miniconda is enabled, then I think your existing Python Windows Registry keys will be altered and uninstallation will probably not restore them.
App\Scriptscould be copied to the new installation, but if this didn't work then reinstalling all packages might have been necessary. Use
pip listto see what packages were installed and their versions. Some were installed by PortablePython. Use
easy_install pipto install pip if it wasn't installed.
If OP has 2.7.x and wants to install a different version, e.g. <=2.6.x or >=3.x.x, then installing different versions side-by-side is fine. You must choose which version of Python (if any) to associate with
*.py files and which you want on your path, although you should be able to set up shells with different paths if you use BASH. AFAIK 2.7.x is backwards compatible with 2.6.x, so IMHO side-by-side installs is not necessary, however Python-3.x.x is not backwards compatible, so my recommendation would be to put Python-2.7 on your path and have Python-3 be an optional version by creating a shortcut to its executable called python3 (this is a common setup on Linux). The official Python default install path on Windows is
If OP is not updating Python, but merely updating packages, they may wish to look into virtualenv to keep the different versions of packages specific to their development projects separate. Pip is also a great tool to update packages. If packages use binary installers I usually uninstall the old package before installing the new one.
I hope this clears up any confusion.