While you can easily get a list of operators I don't think anyone has done the same for all of blender. It would probably be too large anyway.
There is help available directly from python, you can use blender's Python console to access it. Starting with the autocomplete feature, typing in obj.data.materials.
and pressing the Autocomplete button ( or CtrlSpace) will list all items available, even having entered D.objects['
autocomplete will list available object names.
The next option is listing all class attributes, which is methods and variables, so entering dir(C.active_object.data.materials)
into the console gives you -
['__bool__', '__contains__', '__delattr__', '__delitem__', '__doc__', '__doc__',
'__getattribute__', '__getitem__', '__iter__', '__len__', '__module__', '__setattr__',
'__setitem__', '__slots__', 'append', 'bl_rna', 'clear', 'find', 'foreach_get',
'foreach_set', 'get', 'items', 'keys', 'pop', 'rna_type', 'values']
Names surrounded by double underline are 'builtin' implementations as defined by python - eg __len__
is the function called when you use len(C.active_object.data.materials)
Currently of limited use (the scrollback length in the console is too small) is the help function. eg help(C.active_object.data.materials)
will output -
Help on bpy_prop_collection object:
class bpy_prop_collection(bpy_prop)
| Method resolution order:
| bpy_prop_collection
| bpy_prop
| object
|
| Methods defined here:
|
| __bool__(...)
| x.__bool__() <==> x != 0
|
| __contains__(...)
| x.__contains__(y) <==> y in x
|
| __delattr__(...)
| x.__delattr__('name') <==> del x.name
|
<snip>
| ----------------------------------------------------------------------
| Methods inherited from bpy_prop:
|
| __dir__(...)
|
| __eq__(...)
| x.__eq__(y) <==> x==y
|
| __ge__(...)
| x.__ge__(y) <==> x>=y
<snip>
| ----------------------------------------------------------------------
| Data descriptors inherited from bpy_prop:
|
| data
| The data this property is using, *type* :class:`bpy.types.bpy_struct`
|
| id_data
| The :class:`bpy.types.ID` object this datablock is from or None, (not available for all data types)
|
| rna_type
| The property type for introspection
|
| ----------------------------------------------------------------------
| Data and other attributes inherited from bpy_prop:
|
| __new__ = <built-in method __new__ of type object>
| T.__new__(S, ...) -> a new object with type S, a subtype of T