is it possible that python .add_driver command cant create f-curve? If I created a constraint on some bone, in pose mode - let's say Copy Location. And then manually created a driver on the influence (right mouse button &gt; Add Driver), the f-curve with 2 points was created. No problem

But after the same operation, on the same bone  and property, but with python command bpy.data.objects[&quot;Armature&quot;].pose.bones[&quot;some_bone&quot;].constraints[&quot;Copy Location&quot;].driver_add(&quot;influence&quot;)
the f-curve wasn't created, do I miss something?
I found the problem, with the python command .add_driver the generator modifier is automatically generated (m.f.!).

If you want rid of it, you can use
mod = bpy.data.objects[&quot;Armature&quot;].animation_data.drivers[0].modifiers[0]
bpy.data.objects[&quot;Armature&quot;].animation_data.drivers[0].modifiers.remove(mod)