Python 3.6 dependencies for Davinci Resolve Link

Python 3.6 dependencies

Colourlab Creator and Pro versions support DVRLink, Colourlab’s integration feature with DaVinci Resolve, which allows Colourlab to fetch project timelines from DaVinci Resolve and push colour-graded timelines back to Resolve. This feature is implemented using DaVinci Resolve's Python API interface. DaVinci Resolve only supports the Python 3.6 API. Therefore, if Python version 3.6 is not installed on the computer or if Python 3.6 is installed alongside other versions of Python, the DaVinci Resolve Link interface will fail, causing the "Fetch from Resolve" and "Push to Resolve" functions to fail as well.

Resolution

To resolve this issue, our Colourlab installer detects whether Python 3.6 is not installed or is installed alongside other versions of Python and notifies the user that Python 3.6 is required for DaVinci integration to function properly. A corresponding registry change will be made, and Python 3.6 will be installed to the appropriate path on the computer. A pop-up will then appear to obtain the user's consent for these changes. To proceed with the installation, the user must click "Yes." If the user clicks "No," the installation will exit.

Registry changes

DaVinci Resolve expects Python installation paths to be located in the following registry path:

HKEY_CURRENT_USER\Software\Python\PythonCore

Or

HKEY_LOCAL_MACHINE\Software\Python\PythonCore

If Python 3.6 is not detected, our DaVinci integration will fail. If another version of Python, such as Python 3.11, is installed alongside Python 3.6, the path for Python 3.11 will also be available in the registry. DaVinci Resolve may then use the Python 3.11 path, causing our DaVinci integration to fail.

The screenshot above shows a typical installation with both Python 3.6 and Python 3.11 on the computer. In this case, DaVinci Resolve will use Python 3.11 for integrations, but since our integration is only compatible with Python 3.6, it will fail.

To address this, our installer removes the registry entries for Python 3.11 and any other "non-Python 3.6" versions from `HKEY_CURRENT_USER\Software\Python\PythonCore` and `HKEY_LOCAL_MACHINE\Software\Python\PythonCore`, leaving only the 3.6 entry in this HKEY_LOCAL_MACHINE\Software\Python\PythonCore registry location. After installing our Colourlab software, only the following registry entries for 3.6 will remain even if other Python versions are installed.

HKEY_LOCAL_MACHINE\SOFTWARE\Python\PythonCore\3.6

Manual removal of registry keys

Our installer will do this automatically when the user selects "Yes" after being notified via a pop-up dialog that Python 3.6 is required for DaVinci integration to function properly. 

However, if you want to manually remove other versions of Python that are not 3.6, you can do so as follows: 

1. Open the Windows registry by pressing Win+R keys, entering regedit in the Run window, and clicking OK. This will open the Windows Registry.
2. 
3. In the Windows Registry, first navigate to the registry key:

4. HKEY_CURRENT_USER\Software\Python\PythonCore, as shown in the following screenshot. To do this, Click on HKEY_CURRENT_USER, then double-click it to expand.  Locate the subkey Software, expand it, and then find the subkey Python within Software.  Finally, locate PythonCore.

   
   If you see 3.6 under PythonCore, leave it as is. If you see any other Python versions (for example, 3.11 or any value), right-click on that version, and in the context menu, select Delete.

   

5. This will prompt you to remove the key including its subkeys, click Yes on this dialog box.

6. 

7. This will remove the key 3.11 including its subkeys.

   Follow the above steps to remove all non-Python-3.6 versions so that only 3.6 should be available under HKEY_CURRENT_USER\Software\Python\PythonCore

   Similarly follow the same steps to remove the non-Python-3.6 versions from HKEY_LOCAL_MACHINE. The registry key you must navigate to is:

   HKEY_LOCAL_MACHINE\Software\Python\PythonCore as shown in the following screenshot.

   That is, click on the HKEY_LOCAL_MACHINE, then expand it by double clicking it and locate the key named as subkey Software and the locate the subkey Python with-in Software and locate PythonCore.

   If you see 3.6 under PythonCore, leave it as is. If you see any other Python versions, right click on that version and on the context menu, select Delete.

   Follow these steps to remove all non-Python-3.6 versions so that only 3.6 should be available under HKEY_CURRENT_USER\Software\Python\PythonCore

   Now install our Colourlab Software and the Davinci Resolve integration should work without any issues.

   In case the key

   HKEY_CURRENT_USER\Software\Python\PythonCore
   
   or

   HKEY_LOCAL_MACHINE\Software\Python\PythonCore

   is not available, just proceed installing the Colourlab Software.