python hal interface

I have this problem.
In the python script I want to set the signal value like this
"hal.set_s("lenght_tool", value)" but it doesn't work.

The pin value setting works in the same file
"hal.set_p("ini.z.min_limit", val)" , but hal.set_s doesn't work.

I dealt with this problem this way:
cmd = ("halcmd sets length_tool " + tool)
subprocess.check_output(cmd, shell = True)
, but if possible I would prefer to avoid subprocess.

2. The second question is how to set the z-axis offset from the python script.
I need to make a macro that, after measuring the tool, will position g53 z0 in the A-axis rotation axis, as in the screenshot. ?

Marek

There is no set_s command. It was never added.
If you remove the signal, can you just set the bare pin?

I used signal because I can't create a new pin to be able to read and change its value. How is it done? , but I'm more concerned about problem number 2.
How to set the Z axis offset from the script.
Where are the offset values stored? In halcmd show no pin displays these values.

I meant just set the pin directly with no signal or other pin connected.
If you mean set the origin for Z then you must use the linuxcnc python module to call an MDI command.

I have no problem calling the MDI command from a python script.
I need to do exactly as in the screenshot, only from the script.
I don't know if I need to change the value of some pin or signal, or something else.

Just what I needed, it works. Thanks
I still don't know the gcodes very well.