Hi Prathvi,
I don't know about startup using python, but you can start Chimera from the system command line with startup option --nogui and specify input files that could include a python script or Chimera command script for Chimera to execute.  See the following help pages:

Chimera startup:
<https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/startup.html>

System command-line Chimera startup options:
<https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/options.html>

I hope this helps,
Elaine
-----
Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

> On Aug 24, 2023, at 1:18 AM, Prathvi Singh via Chimera-users <chimera-users@cgl.ucsf.edu> wrote:
>
> Hi,
>
> Is it possible to use python to execute commands on the command line of UCSF chimera without actually opening its GUI on the Windows platform?
>
> If not, then how to use python to open its GUI and execute the commands?
>
> I tried the "subprocess.Popen()" and "os.system()" methods to run its GUI by passing the path of chimera executable (version 1.17.1) to them but chimera is displaying an error with exit code 1 (snapshot attached). However, I am able to launch chimeraX (version 1.6.1) via these methods.