When you click a file with the preview window open, windows will show you a preview if windows knows how to do it. But files like .json and .py will not preview.
It would be sometimes useful in the open dialog of any editor to preview a script before opening it. Most open dialogs will inherit the windows explorer preview settings but ....
How do you make windows associate .py files as text like files for the preview pane?
The answer came from this link this link as music2myear mentioned but the accepted answer in that link did not work for me.
What worked for me was 2nd answer in the thread. Member user255627 points out the correct key is HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.py which requires attribute PerceivedType REG_SZ text.
I created an attribute in this key with reg command. You can substitute .py with any extension type and enable a bunch of extensions this way. No need for a external program as mentioned in other thread.
from windows command prompt cmd.exe
reg add HKLM\SOFTWARE\Classes\.py /v PerceivedType /t REG_SZ /d text
If you don't have reg permissions to HKLM (local machine) you can use HKCU (current user)
reg add HKCU\SOFTWARE\Classes\.py /v PerceivedType /t REG_SZ /d text
You can query like this.
reg query HKLM\SOFTWARE\Classes\.py /s
HKEY_LOCAL_MACHINE\SOFTWARE\Classes.py
(Default) REG_SZ Python.File
PerceivedType REG_SZ text
Thanks for the help guys. very useful.
Several years back I hunted for additional preview handlers and found some:
I'm still searching for online references, they might be no longer available.
Aside from this there is a preview-handler-association-editor you can download and use to add extension to a present handler (i.e. add .ini, .inf extension to a text handler.)
I wrote a batch file to enumerate currently present handlers in the registry. It appends found handlers to the batch file itself and displays them afterwards.
@Echo off
Echo/>>%0
Echo ============================================ >>%0
Echo Computername: %ComputerName% Date: %Date% %Time:~0,6% >>%0
reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlers" >>%0
More +9 <%0
Pause
goto :EOF
Sample output:
============================================
Computername: xxxxx Date: 2018-05-08 20:47:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlers
{13D3C4B8-B179-4ebb-BF62-F704173E7448} REG_SZ Windows Contact Preview Handler
{1531d583-8375-4d3f-b5fb-d23bbd169f22} REG_SZ Windows TXT Previewer
{53BEDF0B-4E5B-4183-8DC9-B844344FA104} REG_SZ Microsoft Windows MAPI Preview Handler
{85862EDA-F507-4d5b-ACA9-BB2C34A85682} REG_SZ Microsoft XPS Rich Preview Handler
{8a7cae0e-5951-49cb-bf20-ab3fa1e44b01} REG_SZ Windows Font previewer
{92dbad9f-5025-49b0-9078-2d78f935e341} REG_SZ Microsoft Windows Mail Mime Preview Handler
{a42c2ccb-67d3-46fa-abe6-7d2f3488c7a3} REG_SZ Windows RTF Previewer
{b9815375-5d7f-4ce2-9245-c9d4da436930} REG_SZ Microsoft Windows Mail Mime Preview Handler
{BFD468D2-D0A0-4bdc-878C-E69C2F5B435D} REG_SZ Microsoft Windows Mail Html Preview Handler
{E64164EB-1AE0-4C50-BAEF-A413C2B3A4BC} REG_SZ Microsoft 3MF Shell Thumbnail and Preview Handler
{f8b8412b-dea3-4130-b36c-5e8be73106ac} REG_SZ Microsoft Windows Mail Html Preview Handler
{031EE060-67BC-460d-8847-E4A7C5E45A27} REG_SZ Windows Media Player Rich Preview Handler
{691100A7-2A53-456B-BFE5-6BA17A0AB768} REG_SZ Delphi Asm Preview Handler
{B8961094-8033-4D5B-AAB3-A6BCC76EB7A5} REG_SZ Delphi Cpp Preview Handler
{5B96A782-E9C7-4620-B9DA-4B219BF97AB3} REG_SZ Delphi Xml Preview Handler
{AD8855FB-F908-4DDF-982C-ADB9DE5FF000} REG_SZ Delphi Preview Handler
{f2d43dd7-1233-4d5f-9032-b82a570aee81} REG_SZ MSDN Magazine RESX Preview Handler
{21c532d1-6f1a-4f53-a000-0468a4337ab5} REG_SZ MSDN Magazine MSI Preview Handler
{574fffaa-17f6-44b1-a1b4-177ab5900a51} REG_SZ MSDN Magazine PDF Preview Handler
{df9e65b0-7980-4053-9fcf-6e9af953a9f4} REG_SZ MSDN Magazine Binary Preview Handler
{853f35e3-bd13-417b-b859-1df25be6c834} REG_SZ MSDN Magazine ZIP Preview Handler
{739972dc-dad1-4e8c-bb82-113de4b16b13} REG_SZ MSDN Magazine Resources Preview Handler
{2d6dad69-f296-4be0-ab9e-6ed642aef76b} REG_SZ MSDN Magazine Strong Name Key Preview Handler
{8fd75842-96ae-4ac9-a029-b57f7ef961a8} REG_SZ MSDN Magazine Internet Explorer Preview Handler
{47f228f7-5338-4bb4-af7b-7b52278e1095} REG_SZ MSDN Magazine CSV Preview Handler
{e90a8adf-a1a7-42e8-87b9-02b3bfee31f7} REG_SZ MSDN Magazine Serialized Ink Preview Handler
{dec9ca47-e4cd-4eed-8f1b-b0567a489f0a} REG_SZ MSDN Magazine XAML Preview Handler
{DC6EFB56-9CFA-464D-8880-44885D7DC193} REG_SZ Adobe PDF Preview Handler for Vista
{84F66100-FF7C-4fb4-B0C0-02CD7FB668FE} REG_SZ Microsoft Word previewer
{21E17C2F-AD3A-4b89-841F-09CFE02D16B7} REG_SZ Microsoft Visio previewer
{65235197-874B-4A07-BDC5-E65EA825B718} REG_SZ Microsoft PowerPoint previewer
{00020827-0000-0000-C000-000000000046} REG_SZ Microsoft Excel previewer
I just installed Windows PowerToys which includes a "File Explorer add-ons utility". This utility provides syntax colored previews for "developer files". Supposedly it knows over 150 file types.
I once found a script/registry file somewhere and added some other extensions.
Maybe it will be useful to someone.
Save this as more_preview_extensions.reg
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT.sh]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.cmd]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.php]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.html]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.htm]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.js]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.json]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.java]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.kt]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.cs]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.cpp]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.vb]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.reg]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.md]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.nfo]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.conf]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.cfg]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.xaml]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.cshtml]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.log]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.sln]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.suo]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.csproj]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.ps1]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.kt]
"Content Type"="text/plain"
"PerceivedType"="text"
[HKEY_CLASSES_ROOT.md]
"Content Type"="text/plain"
"PerceivedType"="text"
And by the way - it's a pity that Visual Studio or Visual Studio Code still doesn't have some Preview Handler.
