Thanks for the code. It works as expected.

@s_bach

Thanks for the reference. Reading it at the moment and the whole base container is much more complicated than I thought it would be.

import c4d
from c4d import gui

def main():
    print "---------------------------"

    userdata_entry = 1 # your ID of the userdata

    # construct a DescID for user data
    dId = c4d.DescID(c4d.DescLevel(c4d.ID_USERDATA, c4d.DTYPE_SUBCONTAINER), c4d.DescLevel(userdata_entry,c4d.DTYPE_LONG))

    # read the user data value
    print op.GetParameter(dId, c4d.DESCFLAGS_GET_NONE)

    # write user data value
    userdata_new_value = 42
    op.SetParameter(dId,userdata_new_value,c4d.DESCFLAGS_SET_NONE)
    c4d.EventAdd()

    # list all user data definitions (not values)
    for id, bc in op.GetUserDataContainer():
        print id, bc # pry apart bc for the exact definition (types, min, max...)

if __name__=='__main__':
    main()

This script assumes that your op has a userdata element with the ID 1 which is an integer.
I didn't add the third value for the DescLevels which is 0 in both cases.

Thanks for the response.
Unfortunately, the C++ manual is all foreign to me. The Python documentation doesn't have as many examples compared to the C++.

Anyway, on the page you referred on the section
"User data parameters are stored in a sub-container with the ID ID_USERDATA."

It doesn't have any examples to change parameters but only to get them which is GetParameter. So I guess the proper method would be SetParameter instead of SetFloat?

If so, how do I use the SetParameter?
It requires parameters of (id, param, groupid).

The user data values are stored with the host object and must be accessed using a DescID with c4d.ID_USERDATA. See the DescID Manual.

Sorry for reviving the thread.

But I just want to clarify how do I use the Set methods for an existing UserData.
Basically, a reverse from the question above.

Currently, I have this bracket type code:

space_switch_obj[c4d.ID_USERDATA,3] = 0

I want to change it to a Set method with this one:

space_switch_obj.GetUserDataContainer()[2][1].SetInt32(3,0)

It does not error out but also it doesn't set the parameter to zero.
My logic for the [2] is because it is the third user data with zero being the first
For the [1] is because it is the base container.
For the [3] is because it matches with the [c4d.ID_USERDATA,3] .

Is there a way around this?

P.S.
I'd like to provide you screenshot on the result of the GetUserDataContainer but it's hard to represent since the console do not wrap its result. So the result is a bit long

Interesting. I never knew about the bracket operator being different on a BaseList2D and the BaseContainer.

Thank you for the response. Works as expected. Have a great day ahead!

[] bracket operator in a case of a BaseList2D is an alias for Set/GetParameter.
[] bracket operator in a case of BaseContainer is an alias for SetData / GetData, see __setitem__ and __getitem__.

So you can use them directly.

test = c4d.BaseContainer()
test[1] = "head"
test[2] = "chest"
bc[c4d.DESC_CYCLE] = test

Hope it make sense.
Cheers,
Maxime.