How to update Python

Question

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

User · Answer

Official Python  msi installers are designed to replace    any previous micro release  in x y z  z is  micro   because they are guaranteed to be backward-compatible and binary-compatible a  snapshot   built from source  installation with any micro version  A snapshot installer is designed to replace any snapshot with a lower micro version     See responsible code for 2 x  for 3 x   Any other versions are not necessarily compatible and are thus installed alongside the existing one  If you wish to uninstall the old version  you ll need to do that manually  And also uninstall any 3rd-party modules you had for it    If you installed any modules from bdist wininst packages  Windows  exes   uninstall them before uninstalling the version  or the uninstaller might not work correctly if it has custom logic modules installed with setuptools pip that reside in Lib site-packages can just be deleted afterwards packages that you installed per-user  if any  reside in  APPDATA  Python PythonXY site-packages and can likewise be deleted

User · Answer

I have always just installed the new version on top and never had any issues  Do make sure that your path is updated to point to the new version though

User · Answer

UPDATE  2018-07-06  This post is now nearly 5 years old  Python-2 7 will stop receiving official updates from python org in 2020  Also  Python-3 7 has been released  Check out Python-Future on how to make your Python-2 code compatible with Python-3  For updating conda  the documentation now recommends using conda update --all in each of your conda environments to update all packages and the Python executable for that version  Also  since they changed their name to Anaconda  I don t know if the Windows registry keys are still the same   UPDATE  2017-03-24  There have been no updates to Python x y  since June of 2015  so I think it s safe to assume it has been abandoned   UPDATE  2016-11-11  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   UPDATES  2016-05-16   Anaconda and MiniConda can be used with an existing Python installation by disabling the options to alter the Windows PATH and Registry  After extraction  create a symlink to conda in your bin or install conda from PyPI  Then create another symlink called conda-activate to activate in the Anaconda Miniconda root bin folder  Now Anaconda Miniconda is just like Ruby RVM  Just use conda-activate root to enable Anaconda Miniconda  Portable Python is no longer being developed or maintained    TL DR   Using Anaconda or miniconda  then just execute conda update --all to keep each conda environment updated  same major version of official Python  e g  2 7 5   just install over old  e g  2 7 4    different major version of official Python  e g  3 3   install side-by-side with old  set paths associations to point to dominant  e g  2 7   shortcut to other  e g  in BASH   ln  c Python33 python exe python3     The answer depends    If OP has 2 7 x and wants to install newer version of 2 7 x  then   if using MSI installer from the official Python website  just install over old version  installer will issue warning that it will remove and replace the older version  looking in  installed programs  in  control panel  before and after confirms that the old version has been replaced by the new version  newer versions of 2 7 x are backwards compatible so this is completely safe and therefore IMHO multiple versions of 2 7 x should never necessary  if building from source  then you should probably build in a fresh  clean directory  and then point your path to the new build once it passes all tests and you are confident that it has been built successfully  but you may wish to keep the old build around because building from source may occasionally have issues  See my guide for building Python x64 on Windows 7 with SDK 7 0  if installing from a distribution such as Python x y   see their website  Python x y  has been abandoned  I believe that updates can be handled from within Python x y  with their package manager  but updates are also included on their website  I could not find a specific reference so perhaps someone else can speak to this  Similar to ActiveState and probably Enthought  Python  x y  clearly states it is incompatible with other installations of Python      It is recommended to uninstall any other Python distribution before installing Python x y     Enthought Canopy uses an MSI and will install either into Program Files Enthought or home AppData Local Enthought Canopy App for all users or per user respectively  Newer installations are updated by using the built in update tool  See their documentation  ActiveState also uses an MSI so newer installations can be installed on top of older ones  See their installation notes      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   Sage recommends that you install it into a virtual machine  and provides a Oracle VirtualBox image file that can be used for this purpose  Upgrades are handled internally by issuing the sage -upgrade command  Anaconda can be updated by using the conda command   conda update --all   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 Python PythonCore keys   Anaconda Miniconda makes the following registry edits regardless of the installation options  HKCU Software Python ContinuumAnalytics  with the following keys  Help  InstallPath  Modules and 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  WinPython updates  I think  can be handled through the WinPython  Control Panel  PortablePython is no longer being developed  It had no update method  Possibly updates could be unzipped into a fresh directory and then App lib site-packages and App Scripts could be copied to the new installation  but if this didn t work then reinstalling all packages might have been necessary  Use pip list to see what packages were installed and their versions  Some were installed by PortablePython  Use easy install pip to install pip if it wasn t installed   If OP has 2 7 x and wants to install a different version  e g   lt  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   C  Python33 for 3 3 x  latest 2013-07-29  C  Python32 for 3 2 x  amp c  C  Python27 for 2 7 x  latest 2013-07-29  C  Python26 for 2 6 x  amp c   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

User · Answer

The best solution is to install the different Python versions in multiple paths   eg  C  Python27 for 2 7  and C  Python33 for 3 3   Read this for more info  How to run multiple Python versions on Windows

[python] How to update Python?

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