[python] How to add Python to Windows registry

I've downloaded Enthought Canopy EPD Free (now Canopy Express) from https://www.enthought.com/products/epd/free/ and want to install SciKit Learn (http://sourceforge.net/projects/scikit-learn/files/) which is not part of the basic EPD Free install.

When trying to install it does not find Python in the Windows registry. How do I adjust the registry so that it recognizes the Enthought version of Python?

I faced to the same problem. I solved it by

1. navigate to HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\InstallPath and edit the default key with the output of C:\> where python.exe command.
2. navigate to HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\InstallPath\InstallGroup and edit the default key with Python 3.4

Note: My python version is 3.4 and you need to replace 3.4 with your python version.

Normally you can find Registry entries for Python in HKEY_LOCAL_MACHINE\SOFTWARE\Python\PythonCore\<version>. You just need to copy those entries to HKEY_CURRENT_USER\Software\Python\PythonCore\<version>

I had the same issue while trying to install bots on a Windows Server. Took me a while to find a solution, but this is what worked for me:

1. Open Command Prompt as Administrator
2. Copy this: reg add HKLM\SOFTWARE\Python\PythonCore\2.7\InstallPath /ve /t REG_SZ /d "C:\Python27" /f and tailor for your specifications.
3. Right click and paste the tailored version into Command Prompt and hit Enter!

Anyway, I hope that this can help someone in the future.

When installing Python 3.4 the "Add python.exe to Path" came up unselected. Re-installed with this selected and problem resolved.

I installed ArcGIS Pro 1.4 and it didn't register the Python 3.5.2 it installed which prevented me from installing any add-ons. I resolved this by using the "reg" command in an Administrator PowerShell session to manually create and populate the necessary registry keys/values (where Python is installed in C:\Python35):

reg add "HKLM\Software\Python\PythonCore\3.5\Help\Main Python Documentation" /reg:64 /ve /t REG_SZ /d "C:\Python35\Doc\Python352.chm"
reg add "HKLM\Software\Python\PythonCore\3.5\InstallPath" /reg:64 /ve /t REG_SZ /d "C:\Python35\"
reg add "HKLM\Software\Python\PythonCore\3.5\InstallPath\InstallGroup" /reg:64 /ve /t REG_SZ /d "Python 3.5"
reg add "HKLM\Software\Python\PythonCore\3.5\PythonPath" /reg:64 /ve /t REG_SZ /d "C:\Python35\Lib;C:\Python35\DLLs;C:\Python35\Lib\lib-tk"

I find this easier than using Registry Editor but that's solely a personal preference.

The same commands can be executed in CMD.EXE session if you prefer; just make sure you run it as Administrator.

English

In case that it serves to someone, I leave here the Windows 10 base register for Python 3.4.4 - 64 bit:

Español

Por si alguien lo necesita todavía, este es el registro base de Windows 10 para Python 3.4.4:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Python\PythonCore\3.4]
"DisplayName"="Python 3.4 (64-bit)"
"SupportUrl"="http://www.python.org/"
"Version"="3.4.4"
"SysVersion"="3.4"
"SysArchitecture"="64bit"

[HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\Help]

[HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\Help\Main Python Documentation]
@="C:\\Python34\\Doc\\python364.chm"

[HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\Idle]
@="C:\\Python34\\Lib\\idlelib\\idle.pyw"

[HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\IdleShortcuts]
@=dword:00000001

[HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\InstalledFeatures]

[HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\InstallPath]
@="C:\\Python34\\"
"ExecutablePath"="C:\\Python34\\python.exe"
"WindowedExecutablePath"="C:\\Python34\\pythonw.exe"

[HKEY_CURRENT_USER\Software\Python\PythonCore\3.4\PythonPath]
@="C:\\Python34\\Lib\\;C:\\Python34\\DLLs\\"

You can find the Python executable with this command:

C:\> where python.exe

It should return something like:

C:\Users\<user>\AppData\Local\enthought\Canopy32\User\python.exe

Open regedit, navigate to HKEY_CURRENT_USER\SOFTWARE\Python\PythonCore\<version>\PythonPath and add or edit the default key with this the value found in the first command. Logout, login and python should be found. SciKit can now be installed.

See Additional “application paths” in https://docs.python.org/2/using/windows.html#finding-modules for more details.